Basik Lasik: Tips on Lasik Eye Surgery
Produced in cooperation with the American Academy of Ophthalmology.
If you're tired of wearing glasses or contact lenses, you may be considering Lasik eye surgery — one of the newest procedures to correct vision problems. Before you sign up for the surgery, get a clear picture of what you can expect.
The Facts
•Lasik is surgery to a very delicate part of the eye.
•Hundreds of thousands of people have had Lasik, most very successfully.
•As with any surgery, there are risks and possible complications.
•Lasik may not give you perfect vision. The American Academy of Ophthalmology (AAO) reports that seven out of 10 patients achieve 20/20 vision, but 20/20 does not always mean perfect vision.
•If you have Lasik to correct your distance vision, you'll still need reading glasses around age 45.
•Lasik surgery is too new to know if there are any long-term ill effects beyond five years after surgery.
•Lasik surgery cannot be reversed.
•Most insurance does not cover the surgery.
•You may need additional surgery — called "enhancements" — to get the best possible vision after Lasik.
Understanding Your Eyes
To see clearly, the cornea and the lens must bend — or refract — light rays so they focus on the retina — a layer of light-sensing cells that line the back of the eye. The retina converts the light rays into impulses that are sent to the brain, where they are recognized as images. If the light rays don't focus on the retina, the image you see is blurry. This is called a refractive error. Glasses, contacts and refractive surgery attempt to reduce these errors by making light rays focus on the retina.
Refractive errors are caused by an imperfectly shaped eyeball, cornea or lens, and are of three basic types:
•myopia — nearsightedness; only nearby objects are clear.
•hyperopia — farsightedness; only objects far away are clear.
•astigmatism — images are blurred at a distance and near.
There's also presbyopia — "aging eye." The condition usually occurs between ages 40 and 50, and can be corrected with bifocals or reading glasses.
Are You a Good Candidate for Lasik?
Lasik is not for everyone.
•You should be at least 18 years old (21 for some lasers), since the vision of people younger than 18 usually continues to change.
•You should not be pregnant or nursing as these conditions might change the measured refraction of the eye.
•You should not be taking certain prescription drugs, such as Accutane or oral prednisone.
•Your eyes must be healthy and your prescription stable. If you're myopic, you should postpone Lasik until your refraction has stabilized, as myopia may continue to increase in some patients until their mid- to late 20s.
•You should be in good general health. Lasik may not be recommended for patients with diabetes, rheumatoid arthritis, lupus, glaucoma, herpes infections of the eye, or cataracts. You should discuss this with your surgeon.
•Weigh the risks and rewards. If you're happy wearing contacts or glasses, you may want to forego the surgery.
•Understand your expectations from the surgery. Are they realistic?
•Ask your doctor if you're a candidate for monovision — correcting one eye for distance vision and the other eye for near vision. Lasik cannot correct presbyopia so that one eye can see at both distance and near. However, Lasik can be used to correct one eye for distance and the other for near. If you can adjust to this correction, it may eliminate or reduce your need for reading glasses. In some instances, surgery on only one eye is required. If your doctor thinks you're a candidate, ask about the pros and cons.
Finding a Surgeon
Only ophthalmologists (Eye MDs) are permitted to perform Lasik. Ask your Eye MD or optometrist for a referral to an Eye MD who performs Lasik. The American Academy of Ophthalmology website (www.eyenet.org) feature "Find an Eye MD" can provide you with a list of their members who perform Lasik. Ninety-five percent of all ophthalmologists (Eye MDs) are Academy members. Also, the International Society of Refractive Surgery website (www.LocateAnEyeDoc.com) will provide you with names of refractive surgeons.
Ask your surgeon the following questions:
1.How long have you been doing Lasik surgery?
2.How much experience do you have with the Lasik procedure?
3.How do you define success? What's your success rate? What is the chance for me (with my correction) to achieve 20/20? How many of your patients have achieved 20/20 or 20/40 vision? How many patients return for enhancements? In general 5-15% return.
4.What laser will you be using for my surgery? Make sure your surgeon is using a laser approved by the U.S. Food and Drug Administration (FDA). As of this publication's printing, the FDA has approved five lasers for Lasik; they are manufactured by VISX, Summit, Bausch and Lomb, Nidek and ATC. Contact the FDA for updates.
5.What's involved in after-surgery care?
6.Who will handle after-surgery care? Who will be responsible?
7.What about risks and possible complications?
Risks and Possible Complications
Before the surgery, your surgeon should explain to you the risks and possible complications, and potential side effects, including the pros and cons of having one or both eyes done on the same day. This is the "informed consent" process. Some risks and possible complications include:
•Over- or under-correction. These problems can often be improved with glasses, contact lenses and enhancements.
•Corneal scarring, irregular astigmatism (permanent warping of the cornea), and an inability to wear contact lenses.
•Corneal infection.
•"Loss of best corrected visual acuity" — that is, you would not be able to see as well after surgery, even with glasses or contacts, as you did with glasses or contacts before surgery.
•A decrease in contrast sensitivity, "crispness," or sharpness. That means that even though you may have 20/20 vision, objects may appear fuzzy or grayish.
•Problems with night driving that may require glasses.
•Flap problems, including: irregular flaps, incomplete flaps, flaps cut off entirely, and ingrowth of cells under the flap.
The following side effects are possible, but usually disappear over time. In rare situations, they may be permanent.
•Discomfort or pain
•Hazy or blurry vision
•Scratchiness
•Dryness
•Glare
•Haloes or starbursts around lights
•Light sensitivity
•Small pink or red patches on the white of the eye
Surgery: What to Expect Before, During and After
Before: You'll need a complete eye examination by your refractive surgeon. A preliminary eye exam may be performed by a referring doctor (Eye MD or optometrist). Take your eye prescription records with you to the exams. Your doctor should:
•Dilate your pupils to fine-tune your prescription.
•Examine your eyes to make sure they're healthy. This includes a glaucoma test and a retina exam.
•Take the following measurements:
oThe curvature of your cornea and your pupils. You may be rejected if your pupils are too large.
oThe topography of your eyes to make sure you don't have an irregular astigmatism or a cone-shaped cornea — a condition called Keratoconus.
oThe pachymetry — or thickness — of your cornea. You need to have enough tissue left after your corneas have been cut and reshaped.
•Ask you to sign an informed consent form after a thorough discussion of the risks, benefits, alternative options and possible complications. Review the form carefully. Don't sign until you understand everything in the form.
•If your doctor doesn't think Lasik is right for you, you might consider getting a second opinion; however, if the opinion is the same, believe it.
If you qualify for surgery, your doctor may tell you to stop wearing your contact lenses for a while before the surgery is scheduled because contacts can temporarily change the shape of the cornea. Your cornea should be in its natural shape the day of surgery. Your doctor also may tell you to stop wearing makeup, lotions or perfume for a few days before surgery. These products can interfere with the laser treatment or increase the risk of infection after surgery.
During: Lasik is an outpatient surgical procedure. The only anesthetic is an eye drop that numbs the surface of the eye. The surgery takes 10 to15 minutes for each eye. Sometimes, both eyes are done during the same procedure; but sometimes, surgeons wait to see the result of the first eye before doing the second eye.
The Surgical Procedure: A special device cuts a hinged flap of thin corneal tissue off the outer layer of the eyeball (cornea) and the flap is lifted out of the way. The laser reshapes the underlying corneal tissue, and the surgeon replaces the flap, which quickly adheres to the eyeball. There are no stitches. A shield — either clear plastic or perforated metal — is placed over the eye to protect the flap.
After: Healing is relatively fast, but you may want to take a few days off after the surgery. Be aware that:
•You may experience a mild burning or sensation for a few hours after surgery. Do not rub your eye(s). Your doctor can prescribe a painkiller, if necessary, to ease the discomfort.
•Your vision probably will be blurry the day of surgery, but it will improve considerably by the next day when you return for a follow-up exam.
•If you experience aggravating or unusual side effects, report them to your doctor immediately.
•Do not drive until your vision has improved enough to safely do so.
•Avoid swimming, hot tubs and whirlpools for two weeks after surgery.
Alternatives to Lasik
You may want to discuss some surgical alternatives to Lasik with your eye doctor:
•Photorefractive keratectomy (PRK) is a laser procedure used to reduce myopia, hyperopia and astigmatism without creating a corneal flap.
•Astigmatic keratotomy (AK) is an incisional procedure to reduce astigmatism.
•Intrastromal corneal rings are clear, thin, polymer inlays placed on the eye to correct low myopia only.
Thursday, September 18, 2008
Glaucoma Surgery
The surgical management of glaucoma is offered to patients if drug therapies have not been satisfactory or are inappropriate (e.g., because of the desire to avoid drugs during pregnancy). There are two types of surgical treatment: those using a laser and those using surgical techniques.
During laser treatment for open-angle glaucoma, laser light is aimed at the eye’s trabecular meshwork (the eye’s drainage system). The laser application results in a biological and mechanical reaction in the trabecular meshwork to open the previously blocked meshwork and increases the flow of aqueous fluid from the eye.
The most common conventional (incision) surgical technique is called filtering microsurgery, which involves making a hole through which the excess fluid drains and lowers pressure in the eye. Surgery is used if medication and laser procedures have not been successful or if there is a medical emergency for which pressure must be relieved immediately.
Laser Surgery
Laser surgeries lower intraocular pressure by enhancing the drainage of aqueous fluid or slowing its production. The kind of laser surgery used depends on the type of glaucoma being treated. The length of time the pressure remains lowered depends on the type of laser surgery, the type of glaucoma, and the patient’s individual characteristics.
In some cases, laser surgery may have to be repeated to control internal eye pressure more effectively. Typically, medications will still be needed to maintain fluid pressure within the eye, although a lower dose than previously used may be sufficient. If the laser therapy does not lower the pressure in the eye satisfactorily or the effects wear off, the surgeon may recommend conventional surgery.
What to expect: Laser surgeries are preformed in a doctor’s office in a facility called an ambulatory surgical center or in a hospital. Although some patients may experience a slight stinging sensation, the procedures are usually painless. In some instances, local anesthetic agents are used, in which case there is little if any discomfort.
When the procedure is over, patients may experience blurred vision and some irritation. Normal activities, such as driving and work, may be resumed the next day.
Risks: As with all surgery, there are risks. Risks of laser glaucoma procedures may include a short-term increase in intraocular pressure or an excessive drop in pressure. Both complications are rare and controlled with glaucoma medications. There is a small risk for cataract formation after some types of surgery.
Benefits: Failure to control glaucoma can result in destruction of the optic nerve and permanent blindness of the affected eye. Reducing or preventing raised intraocular pressure by laser therapy is effective in reducing the risk of blindness from glaucoma.
Laser Treatments for Primary Open-Angle Glaucoma
* Selective laser trabeculoplasty (SLT) reduces intraocular pressure by enhancing drainage of excess aqueous fluid. The laser increases drainage by selectively treating certain cell tissue of the trabecular meshwork. The meshwork is at the entrance of the drainage canals. SLT treatments can occasionally be repeated if necessary.
* Argon laser trabeculoplasty (ALT) reduces intraocular pressure by opening the drainage canals of the eye. In many cases, drugs will continue to be needed to maintain safe internal eye pressure after this procedure.
Laser Treatments for Narrow-Angle Glaucoma
* Laser peripheral iridotomy (LPI) reduces excessive intraocular pressure by making a small hole in the iris, the colored part of the eye. Narrow-angle glaucoma occurs when the angle between the iris and cornea, the clear front part of the eye, is too small. The hole allows the iris to move back from the cornea, opening the angle and enhancing aqueous flow.
* Laser cyclophotocoagulation is used to reduce eye pressure by treating the ciliary body, which produces aqueous fluid. The procedure is most commonly used for patients with extensive and end stage glaucoma damage that are not responding to other glaucoma surgeries.
Conventional or Incision Surgery
As noted above, conventional surgery or filtering microsurgery is used when management of glaucoma through medication and laser surgery has failed or is less desirable. Trabeculectomy is most commonly used to prevent or curtail damage to the optic nerve by reducing intraocular pressure. In this procedure, a small incision is made in the sclera of the eye (see Diagram 2) and a flap of tissue is left to cover the incision, allowing slow release of fluid from the inside the eye to its outer layers. The procedure results in the formation of a small blister-like bump called a “bleb.” The bleb is covered by the eyelid and is usually not visible. The excess fluid is carried away as it is absorbed into the bloodstream.
A new modification of trabeculectomy, is non-penetrating deep sclerectomy or viscocanalostomy, where a full-thickness hole in the eye is avoided. Instead, a very deep dissection is performed in the sclera and trabecular meshwork. Intraocular pressure is lowered as fluid oozes through a permeable thin layer of tissue that is created by the viscocanalostomy. A bleb may be formed, but it is usually smaller than one that would be formed following trabeculectomy.
In case of complicated glaucoma or patients who have had multiple surgeries, the use of a tube-shunt or seton is required. These devices, which include the Ahmed Valve, Baervedlt device, or Molteno device, have a plastic tube that is placed in the eye, which drains to an external reservoir placed outside the eye.
What to expect: Microsurgical procedures are performed in an ambulatory surgical center or on an outpatient basis at a hospital. Patients are usually given limited intravenous sedation but may be given general anesthesia. Medication may also be administered around the eye to prevent its movement. Typically, patients are relaxed and experience little if any discomfort.
Risks and benefits: The risks of incision surgery are small. Nevertheless, as with any incision, there is the risk of bleeding and infection. The eye may be red or inflamed, with discomfort and pain. In some instances, the procedure may not reduce eye pressure as intended. Loss of too much pressure can result in a loss of vision. As with laser surgeries, there are occasional instances in which the pressure is too high or too low. When this occurs, medications or additional surgeries may be needed to control the condition. In some instances, cataracts may develop. In very rare circumstances, an eye can be removed as a result of surgery. As with all procedures or medications, the risks need to be balanced with the benefits of saving vision in the affected eye. Failure to control glaucoma can result in destruction of the optic nerve and permanent blindness in the affected eye.
Success rates for glaucoma filtering surgery are about 70% to 90% for at least 1 year. In some instances, the surgically created drainage channel may “heal” or close, in which case high intraocular pressure can recur. The healing or closure of the drainage opening is a natural process that is more likely to develop in younger people. To prevent or retard closure, drugs such as mitomycin-C and 5-fluorouracil may be administered. If necessary, the surgery can be repeated in the same eye.
During laser treatment for open-angle glaucoma, laser light is aimed at the eye’s trabecular meshwork (the eye’s drainage system). The laser application results in a biological and mechanical reaction in the trabecular meshwork to open the previously blocked meshwork and increases the flow of aqueous fluid from the eye.
The most common conventional (incision) surgical technique is called filtering microsurgery, which involves making a hole through which the excess fluid drains and lowers pressure in the eye. Surgery is used if medication and laser procedures have not been successful or if there is a medical emergency for which pressure must be relieved immediately.
Laser Surgery
Laser surgeries lower intraocular pressure by enhancing the drainage of aqueous fluid or slowing its production. The kind of laser surgery used depends on the type of glaucoma being treated. The length of time the pressure remains lowered depends on the type of laser surgery, the type of glaucoma, and the patient’s individual characteristics.
In some cases, laser surgery may have to be repeated to control internal eye pressure more effectively. Typically, medications will still be needed to maintain fluid pressure within the eye, although a lower dose than previously used may be sufficient. If the laser therapy does not lower the pressure in the eye satisfactorily or the effects wear off, the surgeon may recommend conventional surgery.
What to expect: Laser surgeries are preformed in a doctor’s office in a facility called an ambulatory surgical center or in a hospital. Although some patients may experience a slight stinging sensation, the procedures are usually painless. In some instances, local anesthetic agents are used, in which case there is little if any discomfort.
When the procedure is over, patients may experience blurred vision and some irritation. Normal activities, such as driving and work, may be resumed the next day.
Risks: As with all surgery, there are risks. Risks of laser glaucoma procedures may include a short-term increase in intraocular pressure or an excessive drop in pressure. Both complications are rare and controlled with glaucoma medications. There is a small risk for cataract formation after some types of surgery.
Benefits: Failure to control glaucoma can result in destruction of the optic nerve and permanent blindness of the affected eye. Reducing or preventing raised intraocular pressure by laser therapy is effective in reducing the risk of blindness from glaucoma.
Laser Treatments for Primary Open-Angle Glaucoma
* Selective laser trabeculoplasty (SLT) reduces intraocular pressure by enhancing drainage of excess aqueous fluid. The laser increases drainage by selectively treating certain cell tissue of the trabecular meshwork. The meshwork is at the entrance of the drainage canals. SLT treatments can occasionally be repeated if necessary.
* Argon laser trabeculoplasty (ALT) reduces intraocular pressure by opening the drainage canals of the eye. In many cases, drugs will continue to be needed to maintain safe internal eye pressure after this procedure.
Laser Treatments for Narrow-Angle Glaucoma
* Laser peripheral iridotomy (LPI) reduces excessive intraocular pressure by making a small hole in the iris, the colored part of the eye. Narrow-angle glaucoma occurs when the angle between the iris and cornea, the clear front part of the eye, is too small. The hole allows the iris to move back from the cornea, opening the angle and enhancing aqueous flow.
* Laser cyclophotocoagulation is used to reduce eye pressure by treating the ciliary body, which produces aqueous fluid. The procedure is most commonly used for patients with extensive and end stage glaucoma damage that are not responding to other glaucoma surgeries.
Conventional or Incision Surgery
As noted above, conventional surgery or filtering microsurgery is used when management of glaucoma through medication and laser surgery has failed or is less desirable. Trabeculectomy is most commonly used to prevent or curtail damage to the optic nerve by reducing intraocular pressure. In this procedure, a small incision is made in the sclera of the eye (see Diagram 2) and a flap of tissue is left to cover the incision, allowing slow release of fluid from the inside the eye to its outer layers. The procedure results in the formation of a small blister-like bump called a “bleb.” The bleb is covered by the eyelid and is usually not visible. The excess fluid is carried away as it is absorbed into the bloodstream.
A new modification of trabeculectomy, is non-penetrating deep sclerectomy or viscocanalostomy, where a full-thickness hole in the eye is avoided. Instead, a very deep dissection is performed in the sclera and trabecular meshwork. Intraocular pressure is lowered as fluid oozes through a permeable thin layer of tissue that is created by the viscocanalostomy. A bleb may be formed, but it is usually smaller than one that would be formed following trabeculectomy.
In case of complicated glaucoma or patients who have had multiple surgeries, the use of a tube-shunt or seton is required. These devices, which include the Ahmed Valve, Baervedlt device, or Molteno device, have a plastic tube that is placed in the eye, which drains to an external reservoir placed outside the eye.
What to expect: Microsurgical procedures are performed in an ambulatory surgical center or on an outpatient basis at a hospital. Patients are usually given limited intravenous sedation but may be given general anesthesia. Medication may also be administered around the eye to prevent its movement. Typically, patients are relaxed and experience little if any discomfort.
Risks and benefits: The risks of incision surgery are small. Nevertheless, as with any incision, there is the risk of bleeding and infection. The eye may be red or inflamed, with discomfort and pain. In some instances, the procedure may not reduce eye pressure as intended. Loss of too much pressure can result in a loss of vision. As with laser surgeries, there are occasional instances in which the pressure is too high or too low. When this occurs, medications or additional surgeries may be needed to control the condition. In some instances, cataracts may develop. In very rare circumstances, an eye can be removed as a result of surgery. As with all procedures or medications, the risks need to be balanced with the benefits of saving vision in the affected eye. Failure to control glaucoma can result in destruction of the optic nerve and permanent blindness in the affected eye.
Success rates for glaucoma filtering surgery are about 70% to 90% for at least 1 year. In some instances, the surgically created drainage channel may “heal” or close, in which case high intraocular pressure can recur. The healing or closure of the drainage opening is a natural process that is more likely to develop in younger people. To prevent or retard closure, drugs such as mitomycin-C and 5-fluorouracil may be administered. If necessary, the surgery can be repeated in the same eye.
Wavefront Technology
Wavefront-guided LASIK is a promising new technology that provides an advanced method for measuring optical distortions in the eye. Measuring and treating these distortions goes beyond nearsighted, farsighted, and astigmatism determinations that have been used for centuries. As a result, physicians can now customize the LASIK procedure according to each individual patient’s unique vision correction needs. The treatment is unique to each eye, just as a fingerprint is unique. Wavefront systems work by measuring how light is distorted as it passes into the eye and then is reflected back. This creates an optical map of the eye, highlighting individual imperfections.
Wavefront technology functions as a roadmap for LASIK surgery, providing benefits to the patient during both the evaluation and treatment process.
- During the patient evaluation process, wavefront provides the physician comprehensive individual diagnostic information, not available using earlier technologies. Thus, before surgery even begins, the surgeon is better able to determine the appropriate course of treatment.
- During treatment, wavefront allows the surgeon to tailor the laser beam settings, making the surgical procedure itself more precise. In this way, wavefront technology offers the patients sharper, crisper, better quality vision, as well as a reduction in nighttime vision difficulties, such as halos and glare.
Wavefront technology is an adjunct tool used to enhance an already safe and effective procedure. As the most common form of vision correction surgery, LASIK has already benefited millions of patients. The increased safety and the improved quality of vision benefits of customized procedures are an important technological advancement for patients and physicians alike.
Visual Errors
For purposes of this discussion, there are two categories of visual errors or “aberrations:” second-order and higher-order.
Conventional forms of optical correction have been limited to measuring the best spherical and cylindrical visual errors (second-order aberrations), which result in myopia (shortsightedness) or hyperopia (farsightedness) and regular astigmatism (blurriness), and prescribing shperocylindrical lenses in the form of spectacles, contact lenses, and conventional refractive (LASIK) surgery to correct them. Correcting second-order aberrations has the highest impact on acuity, which is the eye’s ability to distinguish object details and shape. At the same time that conventional refractive surgery corrects major, second-order spherical errors, in many cases, it also induces some degree of minor spherical aberrations.
However, about 17 percent of optical errors are higher-order aberrations. If these are minimized, image contrast and special detail are increased. Minimizing higher-order aberrations with wavefront technology by reducing the naturally occurring ones is achievable and may be particularly beneficial to individuals with unusually large amounts of higher-order aberrations.
How Wavefront Works: The wavefront aberrometer
Light can be thought of as traveling in a series of flat sheets, known as wavefronts. To clarify the confusion about light traveling as waves instead of rays, waves are just perpendicular to light rays. These light waves are wrinkled or distorted as they pass through imperfections in the eye. These errors can be displayed on a color map of the wavefront image, which is the tool that is used to diagnose, and then determine corrections, for abberrations in the eye.
There are several ways of analyzing the optical system of the eye using wavefront technology. The most common, the Hartmann-Shack wavefront sensing method, deals with light waves as they exit the eye. In this system, the surgeon or other professional shines a small, low-intensity laser into the eye, and the patient focuses on the light. As that light scatters off of the retina (the rear-most portion of the eye) it passes through the lens, the rear surface of the cornea (the clear, crystalline front part of the eye) and the front surface of the cornea. Thus, the emerging waves of light are distorted by the imperfections in the total visual system of the eye. After leaving the eye, the light passes through an array of many small lenses in the sensing device (called an aberrometer), and is focused into spots, which are recorded by a special camera. The deviation of the spots from their ideal location provides information about focusing imperfections in the visual system.
Wavefront-Guided Treatment
The goal of wavefront-guided laser treatment is to make corrections in the surface of the cornea that compensate for errors in the total visual system. Thus, the amount of wrinkle or error in the wavefront reflected from the back of the eye, as compared to the reference wavefront that was projected into it, defines the compensating optical correction. If the wavefront is retarded in relation to the reference wavefront, the laser must remove more tissue from the part of cornea related to that pattern. If the wavefront is advanced (in front of the referenced wavefront), the laser must remove less tissue. It should be noted that wavefront treatment does induce some minor second-order spherical errors, but to a significantly lesser extent than conventional refractive surgery.
In this way, a wavefront-guided treatment is customized to the characteristics of each eye and intended to minimize higher-order aberrations so that the greatest quality of vision can be achieved.
Wavefront technology is relatively new to the United States. The U.S. Food and Drug Administration (FDA) issued its first approval of a wavefront system in August 2002, and other major US laser manufacturers are expected to receive their approvals in 2003. As the FDA approves systems and they become widely available, patients will have greater access to wavefront technology and treatment.
Wavefront technology functions as a roadmap for LASIK surgery, providing benefits to the patient during both the evaluation and treatment process.
- During the patient evaluation process, wavefront provides the physician comprehensive individual diagnostic information, not available using earlier technologies. Thus, before surgery even begins, the surgeon is better able to determine the appropriate course of treatment.
- During treatment, wavefront allows the surgeon to tailor the laser beam settings, making the surgical procedure itself more precise. In this way, wavefront technology offers the patients sharper, crisper, better quality vision, as well as a reduction in nighttime vision difficulties, such as halos and glare.
Wavefront technology is an adjunct tool used to enhance an already safe and effective procedure. As the most common form of vision correction surgery, LASIK has already benefited millions of patients. The increased safety and the improved quality of vision benefits of customized procedures are an important technological advancement for patients and physicians alike.
Visual Errors
For purposes of this discussion, there are two categories of visual errors or “aberrations:” second-order and higher-order.
Conventional forms of optical correction have been limited to measuring the best spherical and cylindrical visual errors (second-order aberrations), which result in myopia (shortsightedness) or hyperopia (farsightedness) and regular astigmatism (blurriness), and prescribing shperocylindrical lenses in the form of spectacles, contact lenses, and conventional refractive (LASIK) surgery to correct them. Correcting second-order aberrations has the highest impact on acuity, which is the eye’s ability to distinguish object details and shape. At the same time that conventional refractive surgery corrects major, second-order spherical errors, in many cases, it also induces some degree of minor spherical aberrations.
However, about 17 percent of optical errors are higher-order aberrations. If these are minimized, image contrast and special detail are increased. Minimizing higher-order aberrations with wavefront technology by reducing the naturally occurring ones is achievable and may be particularly beneficial to individuals with unusually large amounts of higher-order aberrations.
How Wavefront Works: The wavefront aberrometer
Light can be thought of as traveling in a series of flat sheets, known as wavefronts. To clarify the confusion about light traveling as waves instead of rays, waves are just perpendicular to light rays. These light waves are wrinkled or distorted as they pass through imperfections in the eye. These errors can be displayed on a color map of the wavefront image, which is the tool that is used to diagnose, and then determine corrections, for abberrations in the eye.
There are several ways of analyzing the optical system of the eye using wavefront technology. The most common, the Hartmann-Shack wavefront sensing method, deals with light waves as they exit the eye. In this system, the surgeon or other professional shines a small, low-intensity laser into the eye, and the patient focuses on the light. As that light scatters off of the retina (the rear-most portion of the eye) it passes through the lens, the rear surface of the cornea (the clear, crystalline front part of the eye) and the front surface of the cornea. Thus, the emerging waves of light are distorted by the imperfections in the total visual system of the eye. After leaving the eye, the light passes through an array of many small lenses in the sensing device (called an aberrometer), and is focused into spots, which are recorded by a special camera. The deviation of the spots from their ideal location provides information about focusing imperfections in the visual system.
Wavefront-Guided Treatment
The goal of wavefront-guided laser treatment is to make corrections in the surface of the cornea that compensate for errors in the total visual system. Thus, the amount of wrinkle or error in the wavefront reflected from the back of the eye, as compared to the reference wavefront that was projected into it, defines the compensating optical correction. If the wavefront is retarded in relation to the reference wavefront, the laser must remove more tissue from the part of cornea related to that pattern. If the wavefront is advanced (in front of the referenced wavefront), the laser must remove less tissue. It should be noted that wavefront treatment does induce some minor second-order spherical errors, but to a significantly lesser extent than conventional refractive surgery.
In this way, a wavefront-guided treatment is customized to the characteristics of each eye and intended to minimize higher-order aberrations so that the greatest quality of vision can be achieved.
Wavefront technology is relatively new to the United States. The U.S. Food and Drug Administration (FDA) issued its first approval of a wavefront system in August 2002, and other major US laser manufacturers are expected to receive their approvals in 2003. As the FDA approves systems and they become widely available, patients will have greater access to wavefront technology and treatment.
Prepare for LASIK eye surgery
Before surgery, your eye doctor takes a detailed medical history and uses specialized equipment to carefully measure your cornea, noting the shape and any irregularities.
If you wear contact lenses, you'll need to switch to glasses full time a few weeks before this exam. Contact lenses can distort the shape of your cornea, which could lead to inaccurate measurements and a poor surgical outcome.
Skip your eye makeup and eye cream on the day before and the day of your surgery. Your doctor may also instruct you to clean your eyelashes daily or more often in the days leading up to surgery, to remove debris and minimize your risk of infection.
You'll need to have someone drive you to and from your surgery. Immediately after surgery, you might still feel the affects of medicine given to you before surgery and your vision may be blurry.
Refractive surgery is usually considered elective surgery — which means it isn't vital to your health and well-being. For this reason, Medicare and most insurance companies won't cover the cost of the surgery. So be prepared to pay out-of-pocket for your expenses.
If you wear contact lenses, you'll need to switch to glasses full time a few weeks before this exam. Contact lenses can distort the shape of your cornea, which could lead to inaccurate measurements and a poor surgical outcome.
Skip your eye makeup and eye cream on the day before and the day of your surgery. Your doctor may also instruct you to clean your eyelashes daily or more often in the days leading up to surgery, to remove debris and minimize your risk of infection.
You'll need to have someone drive you to and from your surgery. Immediately after surgery, you might still feel the affects of medicine given to you before surgery and your vision may be blurry.
Refractive surgery is usually considered elective surgery — which means it isn't vital to your health and well-being. For this reason, Medicare and most insurance companies won't cover the cost of the surgery. So be prepared to pay out-of-pocket for your expenses.
Risks
As with any surgery, refractive surgery carries risks, including:
* Undercorrections. If the laser removes too little tissue from your eye, you won't get the vision results you were hoping for. Undercorrections are more common for people who are nearsighted. You may need another refractive surgery (enhancement surgery) within a year to remove more tissue.
* Overcorrections. It's also possible that the laser will remove too much tissue from your eye. Overcorrections may be more difficult to fix than undercorrections.
* Astigmatism. Astigmatism can be caused by uneven tissue removal. This sometimes occurs if your eye moves too much during surgery. It may require additional surgery.
* Glare, halos and double vision. After surgery you may have difficulty seeing at night. You might notice glare, halos around bright lights or double vision. Sometimes these signs and symptoms can be treated with eyedrops that contain a type of corticosteroid, but sometimes a second surgery is required.
* Dry eyes. For the first six months or so after your surgery, as your eyes heal they might feel unusually dry. Your eye doctor might recommend that you use eyedrops during this time. If you experience severe dry eye, you could opt for another procedure to get special plugs put in your tear ducts to prevent your tears from draining away from the surface of your eyes.
* Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection, tearing and swelling. The flap removed during PRK may grow back abnormally.
If you're considering LASIK eye surgery, talk to your doctor about your questions and concerns. He or she can explain how the surgery might benefit you and help put the risks in perspective.
* Undercorrections. If the laser removes too little tissue from your eye, you won't get the vision results you were hoping for. Undercorrections are more common for people who are nearsighted. You may need another refractive surgery (enhancement surgery) within a year to remove more tissue.
* Overcorrections. It's also possible that the laser will remove too much tissue from your eye. Overcorrections may be more difficult to fix than undercorrections.
* Astigmatism. Astigmatism can be caused by uneven tissue removal. This sometimes occurs if your eye moves too much during surgery. It may require additional surgery.
* Glare, halos and double vision. After surgery you may have difficulty seeing at night. You might notice glare, halos around bright lights or double vision. Sometimes these signs and symptoms can be treated with eyedrops that contain a type of corticosteroid, but sometimes a second surgery is required.
* Dry eyes. For the first six months or so after your surgery, as your eyes heal they might feel unusually dry. Your eye doctor might recommend that you use eyedrops during this time. If you experience severe dry eye, you could opt for another procedure to get special plugs put in your tear ducts to prevent your tears from draining away from the surface of your eyes.
* Flap problems. Folding back or removing the flap from the front of your eye during surgery can cause complications, including infection, tearing and swelling. The flap removed during PRK may grow back abnormally.
If you're considering LASIK eye surgery, talk to your doctor about your questions and concerns. He or she can explain how the surgery might benefit you and help put the risks in perspective.
After surgery
Immediately after surgery, your eye may burn or itch and be watery. You'll probably have blurred vision. You may be given pain medication or eyedrops to keep you comfortable for several hours after the procedure. Your eye doctor might also ask you to wear a shield over your eye at night until your eye heals.
Typically you're able to see the day of your surgery, but your vision won't necessarily be better right away. Expect your vision to improve over the next two to three months. Most people who have refractive surgery eventually attain 20/25 or better vision. Your chances for improved vision are based, in part, on how good your vision was before surgery.
Other types of refractive surgery
Your eye doctor may recommend another type of refractive surgery if you're not a good candidate for LASIK eye surgery. These include:
*
Photorefractive keratectomy (PRK). PRK is sometimes used if you have a low to moderate degree of nearsightedness or farsightedness, or if you have nearsightedness with astigmatism. PRK removes the thin surface layer of your cornea (epithelium). Your eye surgeon then uses a laser to flatten your cornea or make its curve steeper.
The exposed surface of your cornea repairs itself, assisted by a contact lens you wear as a bandage over your eye for three or four days after surgery. You might have eye pain for a few days until your cornea heals. It generally takes up to a week for your eye to regenerate the surface tissue that was removed. During this time you'll notice variations in your vision. It may take three to six months before your vision improves completely. Most people undergoing PRK have both eyes done on the same day.
PRK has become less common in recent years because more eye surgeons prefer the LASIK procedure. Healing after LASIK is more predictable and usually involves less discomfort and scarring.
*
Laser epithelial keratomileusis (LASEK). LASEK is similar to LASIK eye surgery and might be an option if you aren't eligible for LASIK. During a LASEK procedure, a much thinner layer — the surface layer (epithelium) — of your cornea is folded back to allow the laser to focus on parts of your cornea that need reshaping. The epithelial flap is then replaced.
If you have very thin corneas, you might be a better candidate for LASEK because the procedure allows your doctor to remove less of your cornea. People who play sports or have jobs that carry a high risk of eye injuries might also prefer LASEK because a thinner flap means less damage to your vision should the flap be torn before it can heal. As with LASIK, the LASEK procedure can be done on both eyes on the same day.
Typically you're able to see the day of your surgery, but your vision won't necessarily be better right away. Expect your vision to improve over the next two to three months. Most people who have refractive surgery eventually attain 20/25 or better vision. Your chances for improved vision are based, in part, on how good your vision was before surgery.
Other types of refractive surgery
Your eye doctor may recommend another type of refractive surgery if you're not a good candidate for LASIK eye surgery. These include:
*
Photorefractive keratectomy (PRK). PRK is sometimes used if you have a low to moderate degree of nearsightedness or farsightedness, or if you have nearsightedness with astigmatism. PRK removes the thin surface layer of your cornea (epithelium). Your eye surgeon then uses a laser to flatten your cornea or make its curve steeper.
The exposed surface of your cornea repairs itself, assisted by a contact lens you wear as a bandage over your eye for three or four days after surgery. You might have eye pain for a few days until your cornea heals. It generally takes up to a week for your eye to regenerate the surface tissue that was removed. During this time you'll notice variations in your vision. It may take three to six months before your vision improves completely. Most people undergoing PRK have both eyes done on the same day.
PRK has become less common in recent years because more eye surgeons prefer the LASIK procedure. Healing after LASIK is more predictable and usually involves less discomfort and scarring.
*
Laser epithelial keratomileusis (LASEK). LASEK is similar to LASIK eye surgery and might be an option if you aren't eligible for LASIK. During a LASEK procedure, a much thinner layer — the surface layer (epithelium) — of your cornea is folded back to allow the laser to focus on parts of your cornea that need reshaping. The epithelial flap is then replaced.
If you have very thin corneas, you might be a better candidate for LASEK because the procedure allows your doctor to remove less of your cornea. People who play sports or have jobs that carry a high risk of eye injuries might also prefer LASEK because a thinner flap means less damage to your vision should the flap be torn before it can heal. As with LASIK, the LASEK procedure can be done on both eyes on the same day.
Tuesday, September 2, 2008
A Brief Note on LASIK
LASIK surgery, a laser eye surgery that is safe, may be used to improve the eyesight of millions who suffer with various sight diagnosis. Laser Assisted Situ Karatomileusis, or LASIK, procedures involve the use of a monochromatic beam that reshapes the cornea of the eye. The machines and laser beams used in these procedures are regulated by the Federal Food and Drug Administration (FDA), insuring patients that the process and lasers used are safe. The FDA oversees the selling of medical equipment in the United States. This means that before doctors may purchase a particular medical instrument or device, this piece must be approved by the FDA, who analyze, thoroughly examine, and test the equipment, to determine the equipment to be safe and to be beneficial to the patient. Once an approval for any device is reached, doctors may have access to the instrument.
The procedure of laser surgery for the eyes has grown in popularity, and doctors use an approved refractive laser system for treating various optical conditions. The most common procedures are used to treat refractive errors such as myopia, hyperopia, and astigmatism, which are conditions related to focus. These diagnosis are commonly referred to as farsightedness, nearsightedness, and various astigmatisms. Other optical diseases are not yet being treated with laser surgery for eyes.
Safe LASIK surgeries can even be performed in a doctor's office. The entire procedure may take less than thirty minutes. There are many precautions used to ensure safety and to prevent complications, such as infection. First, numbing medicines are used to prevent extreme discomfort and irritation to the eyes. Doctors will thoroughly clean the eye and surrounding area, removing any possible articles which could cause further irritations. There are simple devices used to keep the eyelids open . Before the procedure, doctors may also prescribe a mild sedative to patients, helping them to relax and stay calm, increasing the likelihood of success.
The actual process of laser surgery for eyes utilizes an intense beam to open a flap in the cornea. The doctor places a ring around the eye during the surgery, where pressure causes the eye to come forward. At this point, the doctor will begin to use various intense beams to open the cornea and reshape it, allowing refractive light to be more focused, improving vision. After the surgical event, there will be a protective covering which should be used to keep patients from rubbing the area, which may be itching and burning and there may be eye drops prescribed, to keep the area clean. Excessive tearing or watering may occur with some patients and patients should also consult with doctors about all post-op instructions.
Even though laser eye surgery that is safe can help restore vivid eyesight, LASIK surgery for eyes is not for everyone. There are certain conditions which may prohibit this high-tech laser beam procedure. Teenagers under the age of eighteen are not good candidates for LASIK procedures. Young people may still grow, and the eye and cornea may alter with time and growth. There are also those who have a condition called refractive instability. Refractive instability is a condition that causes the eye's ability to focus light to change often, making this diagnosis impractical for this procedure. Also, those who are pregnant, who have fluctuating hormones, diabetes, or other diseases which prevent healing, should not consider this process. Anyone with an autoimmune diagnosis will also be advised against taking risks with surgical procedures.
There are different methods used in LASIK surgeries. Those considering LASIK should obtain a quick education about the surgery and research several different doctors who work with laser equipment. While the actual equipment utilized during a procedure is considered safe by the FDA, doctors and their practices are not actively regulated. Also, costs for laser eye surgery that is safe is also not overseen by the government, so patients will want to make sure and pay competitive prices and that they are receiving the entire treatment paid for. With the popularity of laser surgery for eyes, the industry has grown very competitive. Those investigating or considering LASIK procedures will want to avoid advertising campaigns that sound too good to be true, and find reputable doctors to ensure that the laser eye surgery that is safe, truly is.
The Bible tells us, "Happy is the man that findeth wisdom, and the man that getteth understanding. For the merchandise of it is better than the merchandise of silver, and the gain thereof than fine gold." (Proverbs 3:13-14) No one should be quick to rush into any type of surgery, even a laser eye surgery that is safe. The wise person will seek to get knowledge about any medical procedure before taking risks with the body that God has created and given. It is ultimately the responsibility of the patient to determine what is best for their own bodies and what risks involved will make a medical procedure worth those risks. Spend time in prayer and seek the counsel of others before going forward with laser surgery for eyes.
The procedure of laser surgery for the eyes has grown in popularity, and doctors use an approved refractive laser system for treating various optical conditions. The most common procedures are used to treat refractive errors such as myopia, hyperopia, and astigmatism, which are conditions related to focus. These diagnosis are commonly referred to as farsightedness, nearsightedness, and various astigmatisms. Other optical diseases are not yet being treated with laser surgery for eyes.
Safe LASIK surgeries can even be performed in a doctor's office. The entire procedure may take less than thirty minutes. There are many precautions used to ensure safety and to prevent complications, such as infection. First, numbing medicines are used to prevent extreme discomfort and irritation to the eyes. Doctors will thoroughly clean the eye and surrounding area, removing any possible articles which could cause further irritations. There are simple devices used to keep the eyelids open . Before the procedure, doctors may also prescribe a mild sedative to patients, helping them to relax and stay calm, increasing the likelihood of success.
The actual process of laser surgery for eyes utilizes an intense beam to open a flap in the cornea. The doctor places a ring around the eye during the surgery, where pressure causes the eye to come forward. At this point, the doctor will begin to use various intense beams to open the cornea and reshape it, allowing refractive light to be more focused, improving vision. After the surgical event, there will be a protective covering which should be used to keep patients from rubbing the area, which may be itching and burning and there may be eye drops prescribed, to keep the area clean. Excessive tearing or watering may occur with some patients and patients should also consult with doctors about all post-op instructions.
Even though laser eye surgery that is safe can help restore vivid eyesight, LASIK surgery for eyes is not for everyone. There are certain conditions which may prohibit this high-tech laser beam procedure. Teenagers under the age of eighteen are not good candidates for LASIK procedures. Young people may still grow, and the eye and cornea may alter with time and growth. There are also those who have a condition called refractive instability. Refractive instability is a condition that causes the eye's ability to focus light to change often, making this diagnosis impractical for this procedure. Also, those who are pregnant, who have fluctuating hormones, diabetes, or other diseases which prevent healing, should not consider this process. Anyone with an autoimmune diagnosis will also be advised against taking risks with surgical procedures.
There are different methods used in LASIK surgeries. Those considering LASIK should obtain a quick education about the surgery and research several different doctors who work with laser equipment. While the actual equipment utilized during a procedure is considered safe by the FDA, doctors and their practices are not actively regulated. Also, costs for laser eye surgery that is safe is also not overseen by the government, so patients will want to make sure and pay competitive prices and that they are receiving the entire treatment paid for. With the popularity of laser surgery for eyes, the industry has grown very competitive. Those investigating or considering LASIK procedures will want to avoid advertising campaigns that sound too good to be true, and find reputable doctors to ensure that the laser eye surgery that is safe, truly is.
The Bible tells us, "Happy is the man that findeth wisdom, and the man that getteth understanding. For the merchandise of it is better than the merchandise of silver, and the gain thereof than fine gold." (Proverbs 3:13-14) No one should be quick to rush into any type of surgery, even a laser eye surgery that is safe. The wise person will seek to get knowledge about any medical procedure before taking risks with the body that God has created and given. It is ultimately the responsibility of the patient to determine what is best for their own bodies and what risks involved will make a medical procedure worth those risks. Spend time in prayer and seek the counsel of others before going forward with laser surgery for eyes.
Choosing Your Surgeon
When choosing a surgeon to perform your laser eye surgery there are many factors that you will want to take into consideration:
*
Experience
*
Comprehensive Skills
*
A Dedication to Refractive Surgery
*
State of the Art Equipment
*
Personality, Style, and an Expert Staff
EXPERIENCE
The surgeon you choose should have been performing refractive surgeries for at least three years and performed no fewer then 250 refractive vision correction procedures in the last 12 months. Be sure to speak with recent and past patients that have had the surgery performed by your surgeon. Your surgeon should easily give you a list of 25 or more patients to contact.
SKILLS
Make sure your surgeon is qualified to perform your laser eye surgery. Ask him/her which techniques he/she has been trained in. Your surgeon should have the skills to perform more then one type of refractive surgery. Be wary of surgeons that only offer one or two of the available techniques to correct vision problems. Your surgeon needs to be able to offer you the best surgery available for your condition. Additionally, your surgeon needs to have the skills to perform any enhancements to your eyes that may be required after your initial refractive surgery.
DEDICATION
Is your surgeon dedicated to performing laser eye surgeries? Choosing a surgeon that only performs a couple of procedures a week may not have the experience or skills to perform the surgery required for your vision problems. Additionally, you should ask your surgeon which refractive surgery associations and organizations in which he or she belongs. The manufacturers of the laser surgery equipment also provide documentation to the surgeon for any training provided to him/her.
PERSONALITY
Does your surgeon make you feel comfortable? Are you able to ask your surgeon questions and have them answered in a manner that you understand? The answers to both of these questions should be yes. Your vision is invaluable and you must feel at ease with your surgeon on a personal level. Your surgeon should readily be open to questions and answer them to your satisfaction in an honest and caring manner.
EQUIPMENT
Finally, you want to insure that your surgeon's office is equipped with the latest equipment and manned by an experienced staff. Be sure to verify that your surgeon is using a laser that has been approved by the FDA. Some surgeons have been known to use lasers that have been re-imported, custom-made, or home-made. Furthermore, ask your surgeon if the FDA approved laser he/she is using has been properly serviced and maintained.
STAFF
Take the time to interact with your surgeon's office staff before your procedure. A staff that is dedicated to refractive surgery should be able to take care of your needs and insure that your experience is a rewarding one. There are three different types of eye care professionals usually involved in a person's eye care
*
Experience
*
Comprehensive Skills
*
A Dedication to Refractive Surgery
*
State of the Art Equipment
*
Personality, Style, and an Expert Staff
EXPERIENCE
The surgeon you choose should have been performing refractive surgeries for at least three years and performed no fewer then 250 refractive vision correction procedures in the last 12 months. Be sure to speak with recent and past patients that have had the surgery performed by your surgeon. Your surgeon should easily give you a list of 25 or more patients to contact.
SKILLS
Make sure your surgeon is qualified to perform your laser eye surgery. Ask him/her which techniques he/she has been trained in. Your surgeon should have the skills to perform more then one type of refractive surgery. Be wary of surgeons that only offer one or two of the available techniques to correct vision problems. Your surgeon needs to be able to offer you the best surgery available for your condition. Additionally, your surgeon needs to have the skills to perform any enhancements to your eyes that may be required after your initial refractive surgery.
DEDICATION
Is your surgeon dedicated to performing laser eye surgeries? Choosing a surgeon that only performs a couple of procedures a week may not have the experience or skills to perform the surgery required for your vision problems. Additionally, you should ask your surgeon which refractive surgery associations and organizations in which he or she belongs. The manufacturers of the laser surgery equipment also provide documentation to the surgeon for any training provided to him/her.
PERSONALITY
Does your surgeon make you feel comfortable? Are you able to ask your surgeon questions and have them answered in a manner that you understand? The answers to both of these questions should be yes. Your vision is invaluable and you must feel at ease with your surgeon on a personal level. Your surgeon should readily be open to questions and answer them to your satisfaction in an honest and caring manner.
EQUIPMENT
Finally, you want to insure that your surgeon's office is equipped with the latest equipment and manned by an experienced staff. Be sure to verify that your surgeon is using a laser that has been approved by the FDA. Some surgeons have been known to use lasers that have been re-imported, custom-made, or home-made. Furthermore, ask your surgeon if the FDA approved laser he/she is using has been properly serviced and maintained.
STAFF
Take the time to interact with your surgeon's office staff before your procedure. A staff that is dedicated to refractive surgery should be able to take care of your needs and insure that your experience is a rewarding one. There are three different types of eye care professionals usually involved in a person's eye care
Saturday, August 30, 2008
Lasik Eye Surgery Complaints
A decade after Lasik hit the market, unhappy patients will air their grievances before the Food and Drug Administration Friday as the government begins a major new effort to see if warnings about the risks are strong enough.
How big are those risks? The FDA thinks about 5 percent of patients are dissatisfied, but can't provide more specifics — and is pairing with eye surgeons for a major study expected to enroll hundreds of Lasik patients to try to better understand who has bad outcomes and exactly what their complaints are.
"Clearly there is a group who are not satisfied and do not get the kind of results they expect," FDA medical device chief Dr. Daniel Schultz said Thursday. The study should "help us predict who those patients might be before they have the procedure."
About 7.6 million Americans have undergone some form of laser vision correction, including the $2000-per-eye Lasik. Lasik is quick and, if no problems occur, painless: Doctors cut a flap in the cornea — the clear covering of the eye_ aim a laser underneath it and zap to reshape the cornea for sharper sight.
The vast majority, 95 percent, of patients see more clearly after Lasik — some better than 20/20 — and are happy they had it, said Dr. Kerry Solomon of the Medical University of South Carolina, who led a review of Lasik's safety for the American Society of Cataract and Refractive Surgery.
But one in four patients who seeks Lasik is told they're not a good candidate, he said. And there is little information about just how badly the 5 percent who get it but are dissatisfied actually fare.
Solomon estimates that fewer than 1 percent of patients have severe complications that leave poor vision. Other side effects, however, are harder to pin down. Dry eye, for instance, can range from an annoyance to so severe that people suffer intense pain and need surgery to retain what little moisture their eyes form. That's the kind of question the FDA's new study aims to answer.
Dry eye is common even among people who never have eye surgery, and increases as people age. Solomon says 31 percent of Lasik patients have some degree of it before the surgery, and that about 5 percent worsen afterwards.
But dry-eye specialist Dr. Craig Fowler of the University of North Carolina says other research suggests 48 percent of patients experience some degree of dry eye at least temporarily after Lasik. Cutting the corneal flap severs nerves responsible for stimulating tear production, and how well those nerves heal in turn determines how much dry eye lingers long-term, he said.
Even if the risks are low, that's little consolation to suffering patients.
"As long as you know any ophthalmologist that's wearing glasses, don't get it done," says Steve Aptheker, 59, a Long Island lawyer who was lured by an ad for $999 Lasik and suffered severe side effects that required seven additional surgeries over four years to restore his vision.
The flaps cut in his cornea literally became wrinkled when they were laid back down, blocking his vision and causing severe pain. A few surgeries later, with a different doctor, Aptheker could function better but couldn't drive at night and saw a halo around objects that caused serious distortion even during the day. With more operations as new technology hit the market, Aptheker said today his right eye sees as well as it did with glasses before Lasik, but his left remains fuzzy and requires halo-reducing drops.
The FDA has long known of those side effects, and thus for years has a Web site with warnings for Lasik patients and required that doctors give every potential patient a brochure outlining risks. Friday, the agency will ask its outside advisers if its warning efforts go far enough.
But Lasik has been refined in recent years to offer crisper vision with fewer risks, said Dr. Steven Schallhorn, an ophthalmologist who oversaw the Navy's refractive surgery program until last year when, based in part on his research, the Navy began allowing its aviators to get Lasik.
Schallhorn advises patients to seek what's called "all-laser Lasik" — where a thin flap is created using a more precise laser instead of a blade — combined with "wavefront-guided" software that maps subtle irregularities in the cornea before it's zapped.
How big are those risks? The FDA thinks about 5 percent of patients are dissatisfied, but can't provide more specifics — and is pairing with eye surgeons for a major study expected to enroll hundreds of Lasik patients to try to better understand who has bad outcomes and exactly what their complaints are.
"Clearly there is a group who are not satisfied and do not get the kind of results they expect," FDA medical device chief Dr. Daniel Schultz said Thursday. The study should "help us predict who those patients might be before they have the procedure."
About 7.6 million Americans have undergone some form of laser vision correction, including the $2000-per-eye Lasik. Lasik is quick and, if no problems occur, painless: Doctors cut a flap in the cornea — the clear covering of the eye_ aim a laser underneath it and zap to reshape the cornea for sharper sight.
The vast majority, 95 percent, of patients see more clearly after Lasik — some better than 20/20 — and are happy they had it, said Dr. Kerry Solomon of the Medical University of South Carolina, who led a review of Lasik's safety for the American Society of Cataract and Refractive Surgery.
But one in four patients who seeks Lasik is told they're not a good candidate, he said. And there is little information about just how badly the 5 percent who get it but are dissatisfied actually fare.
Solomon estimates that fewer than 1 percent of patients have severe complications that leave poor vision. Other side effects, however, are harder to pin down. Dry eye, for instance, can range from an annoyance to so severe that people suffer intense pain and need surgery to retain what little moisture their eyes form. That's the kind of question the FDA's new study aims to answer.
Dry eye is common even among people who never have eye surgery, and increases as people age. Solomon says 31 percent of Lasik patients have some degree of it before the surgery, and that about 5 percent worsen afterwards.
But dry-eye specialist Dr. Craig Fowler of the University of North Carolina says other research suggests 48 percent of patients experience some degree of dry eye at least temporarily after Lasik. Cutting the corneal flap severs nerves responsible for stimulating tear production, and how well those nerves heal in turn determines how much dry eye lingers long-term, he said.
Even if the risks are low, that's little consolation to suffering patients.
"As long as you know any ophthalmologist that's wearing glasses, don't get it done," says Steve Aptheker, 59, a Long Island lawyer who was lured by an ad for $999 Lasik and suffered severe side effects that required seven additional surgeries over four years to restore his vision.
The flaps cut in his cornea literally became wrinkled when they were laid back down, blocking his vision and causing severe pain. A few surgeries later, with a different doctor, Aptheker could function better but couldn't drive at night and saw a halo around objects that caused serious distortion even during the day. With more operations as new technology hit the market, Aptheker said today his right eye sees as well as it did with glasses before Lasik, but his left remains fuzzy and requires halo-reducing drops.
The FDA has long known of those side effects, and thus for years has a Web site with warnings for Lasik patients and required that doctors give every potential patient a brochure outlining risks. Friday, the agency will ask its outside advisers if its warning efforts go far enough.
But Lasik has been refined in recent years to offer crisper vision with fewer risks, said Dr. Steven Schallhorn, an ophthalmologist who oversaw the Navy's refractive surgery program until last year when, based in part on his research, the Navy began allowing its aviators to get Lasik.
Schallhorn advises patients to seek what's called "all-laser Lasik" — where a thin flap is created using a more precise laser instead of a blade — combined with "wavefront-guided" software that maps subtle irregularities in the cornea before it's zapped.
Q&A Eye Surgery
"Kcpin" asks: I have presbyopia otherwise no problems with sight. I'm 52, female and I wear 2+ enlargers. Are they harmful? And would I benefit from lazer surgery?
Dr. Soloway: There is no harm in using the over-the-counter readers or magnifier glasses, and +2.00 is about right for your age. They shouldn't be used as a reason to not visit with an eye doctor from time to time (perhaps every 2 years) to be certain that you don't have any silent eye problems such as glaucoma.
Sherry Davis of Bristow, Va., asks: I am in my early 40's and recently went to the eye doctor. I was told that I wasn't a good candidate for laser eye surgery because my prescription hasn't stopped changing. My eyesight is slowly beginning to revert to far-sightedness instead of near-sightedness which I've been for many years. Is it true that I shouldn't get laser eye surgery? The Dr. instead is recommending a treatment using contacts to mold my eyes while I sleep at night, slowly correcting my vision. I would prefer to go the laser surgery route. What would you advise?
Dr. Soloway: One of the first prerequisites of laser eye surgery is that your prescription for distance (not the reading glass prescription) is reasonably stable. Slight changes of a quarter diopter (the measurement for glasses strength) are not typically reasons to not have surgery. The method that your doctor is referring to is called "orthokeratology" and is usually practiced by optometrists (who do not do laser surgery) and not by ophthalmologists (some of whom do perform laser surgery). Orthokeratology can work well depending on the practitioner and the original prescription (weaker prescriptions being easier to treat). Both groups of eye doctors might offer different options based on what is available to them. You might consider getting another local opinion, but be certain to bring as many pairs of old glasses in order to have an assessment of just how much your eyes have been changing.
Brad Dick of Lenexa, Kansas, asks: Are any of the new non-medical eye-focusing programs effective? One program claims a person can, through eye exercise, regain the ability to focus at both distant and close distances. Any truth to these claims?
Dr. Soloway: While there is a good deal of controversy over these non-surgical methods of vision correction, in my practice I have found them to be effective over only a very small range of mild prescriptions.
Frank Kitchen of Folsom, Calif., asks: I have been told that I am not a good candidate for Lasic surgery because I have keloid skin associated with scarring. That was 5 years ago. Have any developments been made that I could now have the surgery? I've told that there are some new procedures that may allow me to have the surgery. I would appreciate your comments on this matter. Thank you for your time and consideration.
Dr. Soloway: Keloid formation is primarily a risk of surface excimer surgery and currently it is not a contraindication for LASIK surgery.
Curt Benefield of San Antonio asks: I have had Lasik surgery about 8 years ago to correct my near-sightedness problem. I am now 56 and have lived with presbyopia for about the past 6 years with a correction of about -1.75. Am I a candidate for corrective surgery?
Dr. Soloway: In the U.S., only a re-treatment to make you nearsighted in one eye with the excimer laser of CK for monovision might help. The other surgical procedures for restoration of reading vision such as SSP (scleral spacing procedure) would not be able to be done as they are investigational and most protocols require no prior eye surgery. One presbyopia investigator's practice is in San Diego and you might contact him for an evaluation: Larry Lothringer, MD.
Carolyn of Brookland, Ark., asks: If you have Amphilophia (lazy eye) in the left eye only and wear bifocals would you be a candidate for laser surgery or would you consider it to dangerous to try? Thank you for your reply in advance.
Dr. Soloway: Monovision may not work well with amblyopia (lazy eye) as the second eye may not see well enough on its own. Depending on the level of weakness, laser surgery, while not more risky, might not be a good option on your only good eye.
Brian Williams of Lenoir City, Tenn., asks: I had RK surgery in 1992 to correct near-sightness. I could read fine without glasses then. Three years ago I had to start wearing glasses again for near-sightness and also for reading. Can surgery correct my near-sightness and allow me to be able to read without glasses?
Dr. Soloway: There is no harm in using the over-the-counter readers or magnifier glasses, and +2.00 is about right for your age. They shouldn't be used as a reason to not visit with an eye doctor from time to time (perhaps every 2 years) to be certain that you don't have any silent eye problems such as glaucoma.
Sherry Davis of Bristow, Va., asks: I am in my early 40's and recently went to the eye doctor. I was told that I wasn't a good candidate for laser eye surgery because my prescription hasn't stopped changing. My eyesight is slowly beginning to revert to far-sightedness instead of near-sightedness which I've been for many years. Is it true that I shouldn't get laser eye surgery? The Dr. instead is recommending a treatment using contacts to mold my eyes while I sleep at night, slowly correcting my vision. I would prefer to go the laser surgery route. What would you advise?
Dr. Soloway: One of the first prerequisites of laser eye surgery is that your prescription for distance (not the reading glass prescription) is reasonably stable. Slight changes of a quarter diopter (the measurement for glasses strength) are not typically reasons to not have surgery. The method that your doctor is referring to is called "orthokeratology" and is usually practiced by optometrists (who do not do laser surgery) and not by ophthalmologists (some of whom do perform laser surgery). Orthokeratology can work well depending on the practitioner and the original prescription (weaker prescriptions being easier to treat). Both groups of eye doctors might offer different options based on what is available to them. You might consider getting another local opinion, but be certain to bring as many pairs of old glasses in order to have an assessment of just how much your eyes have been changing.
Brad Dick of Lenexa, Kansas, asks: Are any of the new non-medical eye-focusing programs effective? One program claims a person can, through eye exercise, regain the ability to focus at both distant and close distances. Any truth to these claims?
Dr. Soloway: While there is a good deal of controversy over these non-surgical methods of vision correction, in my practice I have found them to be effective over only a very small range of mild prescriptions.
Frank Kitchen of Folsom, Calif., asks: I have been told that I am not a good candidate for Lasic surgery because I have keloid skin associated with scarring. That was 5 years ago. Have any developments been made that I could now have the surgery? I've told that there are some new procedures that may allow me to have the surgery. I would appreciate your comments on this matter. Thank you for your time and consideration.
Dr. Soloway: Keloid formation is primarily a risk of surface excimer surgery and currently it is not a contraindication for LASIK surgery.
Curt Benefield of San Antonio asks: I have had Lasik surgery about 8 years ago to correct my near-sightedness problem. I am now 56 and have lived with presbyopia for about the past 6 years with a correction of about -1.75. Am I a candidate for corrective surgery?
Dr. Soloway: In the U.S., only a re-treatment to make you nearsighted in one eye with the excimer laser of CK for monovision might help. The other surgical procedures for restoration of reading vision such as SSP (scleral spacing procedure) would not be able to be done as they are investigational and most protocols require no prior eye surgery. One presbyopia investigator's practice is in San Diego and you might contact him for an evaluation: Larry Lothringer, MD.
Carolyn of Brookland, Ark., asks: If you have Amphilophia (lazy eye) in the left eye only and wear bifocals would you be a candidate for laser surgery or would you consider it to dangerous to try? Thank you for your reply in advance.
Dr. Soloway: Monovision may not work well with amblyopia (lazy eye) as the second eye may not see well enough on its own. Depending on the level of weakness, laser surgery, while not more risky, might not be a good option on your only good eye.
Brian Williams of Lenoir City, Tenn., asks: I had RK surgery in 1992 to correct near-sightness. I could read fine without glasses then. Three years ago I had to start wearing glasses again for near-sightness and also for reading. Can surgery correct my near-sightness and allow me to be able to read without glasses?
Implantable Contact Lenses (ICL's)
If your prescription falls outside the treatment range for Laser Vision Correction, then Implantable Contact Lenses (ICL's) are an option available for you.
Implanted lenses are used for the correction of more severe levels of short sight, long sight and astigmatism. They are similar to a small 'contact lens' which is placed inside the eye instead of sitting on the surface. Benefits include; painfree treatment with rapid visual recovery and very good visual acuity results. Success rate is approximately 95%.
Suitability
Using implanted lenses, patients prescriptions from -23d to +12d with (+/-)7d of astigmatism can be treated. The treatment is also available for patients who are unsuitable for laser treatment due to corneal thickness or after cataract removal. The treatment is not suitable for people over 60 years of age or anyone developing cataracts. People with high glaucoma, recurrent eye infections and other eye diseases may not be suitable.
Consultation
An initial consultation will confirm your suitability and determine the strength of lens required. If you decide to go ahead with treatment, the lenses will be made to your exact specifications and will be ready in 4 - 6 weeks. Consultations for Implantable Contact Lenses (ICL's) are currently available in clinics in London and Croydon.
Treatment
The lens is inserted through a small incision in the side of the cornea and sits in front of the eye's natural lens, just behind the cornea. Antibiotic drops are then administered to avoid infection.
The whole procedure takes around 20 - 30 minutes to complete. You will be able to go home on the same day but it is essential that you have someone to accompany you. For utmost safety in case of infection or rejection, lenses are implanted one at a time, allowing a minimum recovery time of one week between treatments.
After treatment
You will need to rest at the clinic for about an hour after treatment with a bandage over the eye. Visual recovery is rapid, with noticeable improvement within a day or two. You should be able to drive and be back to work within two weeks of the procedure.
Aftercare
You will need to be seen by the treating doctor on the day after surgery, so an overnight stay in a local hotel may be desirable. You are then seen after one week when the second eye may be operated on. Aftercare visits are then required after one month and three months and then as directed by the surgeon.
Implanted lenses are used for the correction of more severe levels of short sight, long sight and astigmatism. They are similar to a small 'contact lens' which is placed inside the eye instead of sitting on the surface. Benefits include; painfree treatment with rapid visual recovery and very good visual acuity results. Success rate is approximately 95%.
Suitability
Using implanted lenses, patients prescriptions from -23d to +12d with (+/-)7d of astigmatism can be treated. The treatment is also available for patients who are unsuitable for laser treatment due to corneal thickness or after cataract removal. The treatment is not suitable for people over 60 years of age or anyone developing cataracts. People with high glaucoma, recurrent eye infections and other eye diseases may not be suitable.
Consultation
An initial consultation will confirm your suitability and determine the strength of lens required. If you decide to go ahead with treatment, the lenses will be made to your exact specifications and will be ready in 4 - 6 weeks. Consultations for Implantable Contact Lenses (ICL's) are currently available in clinics in London and Croydon.
Treatment
The lens is inserted through a small incision in the side of the cornea and sits in front of the eye's natural lens, just behind the cornea. Antibiotic drops are then administered to avoid infection.
The whole procedure takes around 20 - 30 minutes to complete. You will be able to go home on the same day but it is essential that you have someone to accompany you. For utmost safety in case of infection or rejection, lenses are implanted one at a time, allowing a minimum recovery time of one week between treatments.
After treatment
You will need to rest at the clinic for about an hour after treatment with a bandage over the eye. Visual recovery is rapid, with noticeable improvement within a day or two. You should be able to drive and be back to work within two weeks of the procedure.
Aftercare
You will need to be seen by the treating doctor on the day after surgery, so an overnight stay in a local hotel may be desirable. You are then seen after one week when the second eye may be operated on. Aftercare visits are then required after one month and three months and then as directed by the surgeon.
Millions ignore poor eyesight
Millions of people in the UK are turning a blind eye to their own sight problems, a survey has found. By doing so they are putting themselves and others at risk.
The study of just under 1,000 adults who had not had eyesight correction, found many put off wearing contact lens or glasses even when they suspected they might need them.
The figures suggest that as many as 2.5m Britons who should be seeking help for eyesight problems have failed to do so.
Each person was given a basic eye test, and asked for their opinions on contact lens, glasses and laser eye surgery.
More than one in three (35%) failed the eye test - but of these 33% said they were not surprised and worryingly, 65% were car drivers.
Researcher Dr June McNicholas, a psychologist at Warwick University, said the results suggested that many people had taken a conscious decision not to have their vision corrected.
The study of just under 1,000 adults who had not had eyesight correction, found many put off wearing contact lens or glasses even when they suspected they might need them.
The figures suggest that as many as 2.5m Britons who should be seeking help for eyesight problems have failed to do so.
Each person was given a basic eye test, and asked for their opinions on contact lens, glasses and laser eye surgery.
More than one in three (35%) failed the eye test - but of these 33% said they were not surprised and worryingly, 65% were car drivers.
Researcher Dr June McNicholas, a psychologist at Warwick University, said the results suggested that many people had taken a conscious decision not to have their vision corrected.
Lasik - News
Amidst a declining economy, people are doing just about anything to save a few bucks on their coveted elective surgical procedures. Just because we're about to enter a recession doesn't mean people don't still want their breast augmentations, face lifts, teeth whitening and LASIK surgery.
For the non-squemish and non-bashful, there is a new trend that is saving people as much as 50% on some of their elective procedures. If you agree to have your procedure broadcast LIVE on YouTube (or a number of other popular video posting sites), you may be offered money off of your surgery.
Not all surgeons are participating, but the ones who are are coming from a purely advertising mindset. People who log on to the video sharing websites can watch the procedure, and the video acts as a real-life, real time marketing tool for the surgeons. They're able to show off their talents, and walk viewers through the procedure step by step.
You may not be interested in watching other people's surgeries, ,but if you don't mind being filmed to save some dough, inquire to your local LASIK center. As the procedure only takes five minutes or so, many LASIK surgeons are interested in doing these types of alterna-marketing ideas to entice new patients.
For the non-squemish and non-bashful, there is a new trend that is saving people as much as 50% on some of their elective procedures. If you agree to have your procedure broadcast LIVE on YouTube (or a number of other popular video posting sites), you may be offered money off of your surgery.
Not all surgeons are participating, but the ones who are are coming from a purely advertising mindset. People who log on to the video sharing websites can watch the procedure, and the video acts as a real-life, real time marketing tool for the surgeons. They're able to show off their talents, and walk viewers through the procedure step by step.
You may not be interested in watching other people's surgeries, ,but if you don't mind being filmed to save some dough, inquire to your local LASIK center. As the procedure only takes five minutes or so, many LASIK surgeons are interested in doing these types of alterna-marketing ideas to entice new patients.
Is Laser Eye Surgery Safer Than Wearing Contact Lenses?
After comparing data from several recent studies, an Oregon ophthalmology professor has concluded that laser eye surgery may be safer than wearing contact lenses long-term.
The chance of vision loss appears more likely with long-term contact lens wear than with laser eye surgery, said William Mathers, MD, of Oregon Health & Science University Casey Eye Institute in Portland, Ore.
"Several times a year, I have patients who lose eyes from complications because they've been wearing contacts and they've gotten an infection. By this, I mean their eyes have to be physically removed from their bodies," Mathers said in a news release.
"It's not that contacts aren't good. They're better than they've ever been. But one cannot assume contacts are safer."
In contrast, Mathers said the safety record of 18,000 laser eye surgery procedures conducted at Portland's Casey Vision Correction Center demonstrates that no patient has ever lost vision equivalent to two lines on an eye chart. Mathers also cited results from more than 32,000 U.S. military personnel undergoing laser eye surgery in which one in 1,250 lost one line of vision. There were no reports of loss of two lines or more of vision.
Mathers said that between 20 million and 25 million U.S. citizens wear contact lenses. About one million people in the United States undergo laser eye surgery annually.
The chance of vision loss appears more likely with long-term contact lens wear than with laser eye surgery, said William Mathers, MD, of Oregon Health & Science University Casey Eye Institute in Portland, Ore.
"Several times a year, I have patients who lose eyes from complications because they've been wearing contacts and they've gotten an infection. By this, I mean their eyes have to be physically removed from their bodies," Mathers said in a news release.
"It's not that contacts aren't good. They're better than they've ever been. But one cannot assume contacts are safer."
In contrast, Mathers said the safety record of 18,000 laser eye surgery procedures conducted at Portland's Casey Vision Correction Center demonstrates that no patient has ever lost vision equivalent to two lines on an eye chart. Mathers also cited results from more than 32,000 U.S. military personnel undergoing laser eye surgery in which one in 1,250 lost one line of vision. There were no reports of loss of two lines or more of vision.
Mathers said that between 20 million and 25 million U.S. citizens wear contact lenses. About one million people in the United States undergo laser eye surgery annually.
Aspiring Astronauts May Now Undergo LASIK
Aspiring astronauts who have undergone "all laser" LASIK can now be considered for NASA's space program because of a recent policy change.
Previously, LASIK was considered unsafe for astronauts in extreme conditions such as liftoff because of a hinged flap created on the eye's surface. After the cornea is reshaped by an excimer laser, the flap is replaced as a type of natural bandage.
Healing times are much faster because of the flap used with LASIK. But NASA officials feared that even a healed flap could become dislodged under extreme conditions.
Now, NASA officials say that modern wavefront-guided LASIK using flaps created by a special laser (femtosecond) known as IntraLase has a safety profile good enough to clear the vision correction procedure for astronauts.
Previously, LASIK was considered unsafe for astronauts in extreme conditions such as liftoff because of a hinged flap created on the eye's surface. After the cornea is reshaped by an excimer laser, the flap is replaced as a type of natural bandage.
Healing times are much faster because of the flap used with LASIK. But NASA officials feared that even a healed flap could become dislodged under extreme conditions.
Now, NASA officials say that modern wavefront-guided LASIK using flaps created by a special laser (femtosecond) known as IntraLase has a safety profile good enough to clear the vision correction procedure for astronauts.
Does Quality of Life Improve After LASIK?
Visual function as measured by what's seen on an eye chart is one way of determining success following a LASIK surgery procedure.
But the U.S. Food and Drug Administration (FDA) wants to clarify whether LASIK actually improves quality of life.
To do this, the agency will undertake a major study in 2009 in cooperation with the National Eye Institute, American Society of Cataract and Refractive Surgery and the American Academy of Ophthalmology.
The study will assess quality of life following LASIK based on factors such as general satisfaction beyond how eyesight is traditionally assessed.
Between 1998 and 2006, the FDA reported receiving 140 comments from people unhappy with the outcomes of LASIK procedures.
But the U.S. Food and Drug Administration (FDA) wants to clarify whether LASIK actually improves quality of life.
To do this, the agency will undertake a major study in 2009 in cooperation with the National Eye Institute, American Society of Cataract and Refractive Surgery and the American Academy of Ophthalmology.
The study will assess quality of life following LASIK based on factors such as general satisfaction beyond how eyesight is traditionally assessed.
Between 1998 and 2006, the FDA reported receiving 140 comments from people unhappy with the outcomes of LASIK procedures.
Study Finds High Satisfaction Rate With LASIK
About 95 percent of the more than 16.3 million people worldwide who have undergone LASIK eye surgery are satisfied with their results, according to the American Society of Cataract and Refractive Surgery (ASCRS).
"We find that there is solid evidence in the world's scientific literature to affirm that there is an exceptionally high level of satisfaction in patients who have had LASIK surgery," said ASCRS president Richard L. Lindstrom, MD.
ASCRS based its conclusions on a review of nearly 3,000 peer-reviewed articles appearing in scientific and medical journals worldwide.
Lindstrom acknowledged that risks are still involved and some outcomes are unfavorable, which is why eye surgeons continually seek to improve technology and techniques.
Researchers who reviewed scientific literature said successful outcomes also involve selecting appropriate candidates for LASIK based on factors such as eye health.
"We find that there is solid evidence in the world's scientific literature to affirm that there is an exceptionally high level of satisfaction in patients who have had LASIK surgery," said ASCRS president Richard L. Lindstrom, MD.
ASCRS based its conclusions on a review of nearly 3,000 peer-reviewed articles appearing in scientific and medical journals worldwide.
Lindstrom acknowledged that risks are still involved and some outcomes are unfavorable, which is why eye surgeons continually seek to improve technology and techniques.
Researchers who reviewed scientific literature said successful outcomes also involve selecting appropriate candidates for LASIK based on factors such as eye health.
Refractive Surgery
One of the most advanced techniques of eye surgery today is the so-called refractive surgery. This type of surgical procedure may decrease or even eliminate a person’s dependency on glasses or contact lenses. This procedure is called refractive surgery since it affects the refractive state of the eye, which may cause common vision disorders such as myopia, hyperopia and astigmatism. Currently, the most common type of refractive surgery utilizes laser to reshape the patient’s cornea and eliminate the subtle alterations that cause eye disorders. Surveys point that refractive surgery it’s becoming so widespread and results so successful that nearly 1 million of surgeries are expected to be performed in 2006, in the USA alone.
Sunday, August 17, 2008
Favourite Film on your Glasses
The 29-year-old optician first began experimenting with vinyl and plastic glass frames about eight years ago and now sells a range of Cinematique eyewear with clips from the silver screen worked into the frame.
"I began testing all sorts of plastic until I found my father's record collection, and then I started recycling those without his knowledge," Tipton told Reuters.
That's when Tipton, who grew up in the United States with a Hungarian mother, decided to set up his funky eyewear business.
Now he, along with his brother, are based in Budapest and their collection is sold across Europe and North America.
Their Cinematique frames are made by recycling 35mm and 16mm movies. The film is collected from cinemas and dates from after 1989.
"They (customers) tell us they'd like a film from Woody Allen or they want Mission Impossible 3 in their frame or they want a picture of some famous actor, then we will make it here and ship it to them," Tipton said.
Tipton moved to Hungary at the start of this decade and is now targeting increasingly affluent eastern European customers with a list of about 300 films to choose from.
The frames are designed on a computer and a company in Italy manufactures them. The front of the frames is made by a sister company in neighboring Slovakia.
Not all films make good material though, as the images must have bold colors and lots of contrast.
Tipton said a favorite is the 2003 action movie Once Upon a Time in Mexico, which stars Antonio Banderas as hitman El Mariachi alongside Johnny Depp as a psychotic CIA agent.
"There are explosions everywhere, contrast, people flying, jumping, which brings out an added dimension."
"I began testing all sorts of plastic until I found my father's record collection, and then I started recycling those without his knowledge," Tipton told Reuters.
That's when Tipton, who grew up in the United States with a Hungarian mother, decided to set up his funky eyewear business.
Now he, along with his brother, are based in Budapest and their collection is sold across Europe and North America.
Their Cinematique frames are made by recycling 35mm and 16mm movies. The film is collected from cinemas and dates from after 1989.
"They (customers) tell us they'd like a film from Woody Allen or they want Mission Impossible 3 in their frame or they want a picture of some famous actor, then we will make it here and ship it to them," Tipton said.
Tipton moved to Hungary at the start of this decade and is now targeting increasingly affluent eastern European customers with a list of about 300 films to choose from.
The frames are designed on a computer and a company in Italy manufactures them. The front of the frames is made by a sister company in neighboring Slovakia.
Not all films make good material though, as the images must have bold colors and lots of contrast.
Tipton said a favorite is the 2003 action movie Once Upon a Time in Mexico, which stars Antonio Banderas as hitman El Mariachi alongside Johnny Depp as a psychotic CIA agent.
"There are explosions everywhere, contrast, people flying, jumping, which brings out an added dimension."
Friday, August 15, 2008
Orbscan
We’re not going to talk a lot about Orbscans because, well, first, we don’t know a whole lot about them, and, second, as far as we know they aren’t much good at what standard topographers do, but what they are good at is corneal thickness.
Corneal thickness is a very important piece of information for diagnosing certain complications from refractive surgery. And this is so important that they measured it before surgery, probably with an Orbscan (which you should ask for a copy of, incidentally), in order to make sure your corneas were thick enough to do surgery safely in the first place. Now, after surgery, the Orbscan can still indicate whether the cornea was made any thinner than intended, particularly important if you are considering further surgical treatment.
It should be noted that Orbscans do not do this flawlessly (they are simply calculating averages over certain areas) and even if they did, for LASIK patients it would be of limited use, because all it really tells is the total thickness including the LASIK flap. Remember that now there are two distinct parts of the cornea: the flap, and everything underneath.
The part you might have a reason to worry about is the thickness of the stroma under the flap. (Although come to think of it, equally, if your flap was really sloppy, and is thicker in some parts than others, you’re going to have reasons to worry about it too.) That is because if it gets too thin, the pressure in your eye may cause bulging, which does not do nice things to your vision and may be a progressive condition called corneal ectasia. So how can you measure the stroma under the flap? Most don’t. They simply take the total thickness at the thinnest point (as indicated on the Orbscan), say, 420 microns, and subtract the thickness the flap was supposed to be, say, 160 microns. That leaves 260 microns. But suppose the flap is thicker? There could be less stroma. Or if thinner, more stroma. The flap can be analysed in better detail using VHF digital ultrasound (Artemis). That is not widely available, but you can get it in London.
Corneal thickness is a very important piece of information for diagnosing certain complications from refractive surgery. And this is so important that they measured it before surgery, probably with an Orbscan (which you should ask for a copy of, incidentally), in order to make sure your corneas were thick enough to do surgery safely in the first place. Now, after surgery, the Orbscan can still indicate whether the cornea was made any thinner than intended, particularly important if you are considering further surgical treatment.
It should be noted that Orbscans do not do this flawlessly (they are simply calculating averages over certain areas) and even if they did, for LASIK patients it would be of limited use, because all it really tells is the total thickness including the LASIK flap. Remember that now there are two distinct parts of the cornea: the flap, and everything underneath.
The part you might have a reason to worry about is the thickness of the stroma under the flap. (Although come to think of it, equally, if your flap was really sloppy, and is thicker in some parts than others, you’re going to have reasons to worry about it too.) That is because if it gets too thin, the pressure in your eye may cause bulging, which does not do nice things to your vision and may be a progressive condition called corneal ectasia. So how can you measure the stroma under the flap? Most don’t. They simply take the total thickness at the thinnest point (as indicated on the Orbscan), say, 420 microns, and subtract the thickness the flap was supposed to be, say, 160 microns. That leaves 260 microns. But suppose the flap is thicker? There could be less stroma. Or if thinner, more stroma. The flap can be analysed in better detail using VHF digital ultrasound (Artemis). That is not widely available, but you can get it in London.
Topography
Topography means a sort of relief map of your cornea. They are the scans where you see a big colourful circley-sort of thing with several different colours ranging from red to blue. The colours equate to different thicknesses of the cornea.
We have a real grudge about the fact that it can be so difficult to get straight answers about what your topographies MEAN. It simply can’t be all that hard. I mean, they have done these surgeries on how many millions of people? But, sadly, they don’t seem to have bothered to do any analysis at all of what makes for a GOOD topography, so now they don’t seem to agree with each other on rules about what constitutes a BAD topography (other than that no patient of theirs is likely to have one). Fortunately we patients have not been left altogether out to dry as there are many doctors who have experience with these problems and because they have been kind enough to spend time helping us, we tend to bombard them with topographies asking for advice.
You will learn very quickly, if you already haven’t, that you’d better get copies of your topographies if you want any help diagnosing your situation. There are people who are willing to help, but you’ve got to do your job by asking for copies.
Axial topography
We’re going to talk mostly about standard topography because it’s probably what will be most relevant to you. There are a number of topographers that fall into this category, with Humphrey Systems perhaps one of the most popular.
First, let’s talk about which of those colourful circles we’re interested in. On a Humphrey, it’s called an Axial Map. And we really hope you have Humphrey topos, but if you don’t, look for something called an Axial Map (or close to it) anyway.
Next, make sure you know which eye is which as they are labelled OD (right eye) and OS (left eye).
Next, let’s talk about resolution. There’s a key to one side of the scan showing what resolution was used. What you really want is one colour change for at least every _ dioptre, meaning, for example, that 42.0 is green and 43.0 is yellow and there’s a few discernible shades in between. Obviously, the greater the resolution, the less information the scan will give you. If resolution is set too high, everything is going to look beautiful. If it is set lower, you actually have a chance of seeing useful information. (Remember when you had to decide between a 2.0 megapixel and a 3.0 megapixel digital camera.... well, this is a lot more important.)
Now, down to business.
I’m taking a big risk in talking about topographies. Why? On the one hand, I’m not an expert. On the other hand, I’ve been told a lot of nonsense by people who should be experts. On the other hand, one or two experts whose opinions I value think it’s complicated stuff and are sometimes hesitant to pronounce judgement on certain kinds of things. On the other hand, one or two other experts whose scientific honesty I value think it is almost as simple as it ought to be and that there are actually some reasonable rules you can apply. On the other hand, when one has seen piles of topographies of people with horrible optical results from LASIK, presumably one ought to be able to identify certain common aspects contributing to the horribleness of their results. On the other hand, one never seems to see post-operative topographies from people with anywhere from acceptable to good to excellent results, because they’re simply so happy their doctor never bothered, and one wonders whether, if nobody’s analysing good topos, how does one know what good topos ought to look like? On the other hand...
For heaven’s sakes, how many hands can a person be expected to count on? Topos, tapas. I’m tired of debating with myself and will simply take the leap.
So, I’m going to take a stab at one or two basic points, and hopefully wherever I am wrong or incomplete, the medical community will rise up in wrath and pummel me with excellent, user-friendly scientific studies showing me the error of my ways in which case I will hasten to revise this text. Incidentally, at the time of this writing a trusted MD friend is engaged in research on this very topic and I am impatiently awaiting the results so that I can get a clearer view on what makes for good topos.
1. You should be looking at something that looks vaguely like a blue circle in a sea of red, with the bluish part extending for a certain way (across at least a couple of the boxes in the grid) then giving way to a progression of colours working their way up the rainbow: green, yellow, and orange, then red.
2. You should be able to identify your functional optical zone in there somewhere. The functional optical zone is the part that has been given full refractive error correction by the laser. The functional optical zone should be close to, but then again may not be anywhere near, the planned ablation zone as indicated on the operative report. That was the plan. This is the reality. We know people with FOZs as small as 2.5mm where their laser was programmed for 5.5. A little bit of this can be due to what’s known as ablation shrinkage, but the rest must be attributed to either what the laser did, or how badly the cornea was bothered by what the laser did.
3. Really small FOZs are Bad Things.
4. FOZs that are not all that small but are still smaller than your pupil size in dim light or dark are also Bad Things.
5. If you can’t identify your FOZ at all because there are so many colours swimming around right in the centre of the ablation, that is a Bad Thing.
6. Now, look at that blue circle (if there is one) or at any rate the central 6mm of your cornea. If it’s reasonably round, that means it had a centre. Try to identify the centre.
7. If the centre of the blue circle is not somewhere very near to the centre of your pupil, that is a very Bad Thing.
8. If the centre of the blue circle is perfectly aligned with the centre of your pupil, but there is a little X indicating your line of sight and that’s kind of offset from your pupil, and you had a high prescription, that might be a Bad Thing. (There is an industry argument over whether the ablation should be centred on the pupil or centred on the line of sight. Kind of important, like, boys, we need to decide whether we’re aiming to wing him or get him right in the heart.
9. Now, look at the central 6mm of your topography, and forget about whether it’s all the same colour (it probably isn’t or you wouldn’t be here). Do you see anything that looks like a bow tie, or a bug splat, or islands swimming around? That might not be a good thing. Now use the key that shows what fraction of a dioptre is represented by a colour. Are any of those fancy things more than 0.5 dioptre different in colour than the stuff around them? That indicates a Bad Thing.
10. Looking at that same central 6mm, use the key and find the minimum and maximum number of dioptres within that circle, and add up the different colours. If you are seeing 3 or more colours, and the minimum and maximum are 1.00 dioptre or more apart from each other, those are Bad Things. You should not have to be looking out at the world through all different kinds of refractive powered cornea. You might still be able to read an eye chart especially if the 1mm at the centre of your cornea is just the right power, but that doesn’t help too much with real life.
11. If your pupil size in dim light is greater than 6mm (which is probably the case: it is statistically true for half the population, and since you’ve got a bad result from surgery, it’s rather more likely to be true of you) look at the area between 6mm and however large your pupil is in dim light, and apply rules 9 and 10, and see if you find any more Bad Things.
By now, you are getting the idea. You ought to have a reasonably nice looking lasered area on your cornea that goes out somewhere at least close to where your pupil’s going to extend to. If you don’t, nobody should be surprised that you have some significant vision disturbances. If you do, you may still have plenty of reasons for vision disturbances when we get down to the dirty details. You’ll have to stay tuned for when The Lone Dog starts talking about that.
We have a real grudge about the fact that it can be so difficult to get straight answers about what your topographies MEAN. It simply can’t be all that hard. I mean, they have done these surgeries on how many millions of people? But, sadly, they don’t seem to have bothered to do any analysis at all of what makes for a GOOD topography, so now they don’t seem to agree with each other on rules about what constitutes a BAD topography (other than that no patient of theirs is likely to have one). Fortunately we patients have not been left altogether out to dry as there are many doctors who have experience with these problems and because they have been kind enough to spend time helping us, we tend to bombard them with topographies asking for advice.
You will learn very quickly, if you already haven’t, that you’d better get copies of your topographies if you want any help diagnosing your situation. There are people who are willing to help, but you’ve got to do your job by asking for copies.
Axial topography
We’re going to talk mostly about standard topography because it’s probably what will be most relevant to you. There are a number of topographers that fall into this category, with Humphrey Systems perhaps one of the most popular.
First, let’s talk about which of those colourful circles we’re interested in. On a Humphrey, it’s called an Axial Map. And we really hope you have Humphrey topos, but if you don’t, look for something called an Axial Map (or close to it) anyway.
Next, make sure you know which eye is which as they are labelled OD (right eye) and OS (left eye).
Next, let’s talk about resolution. There’s a key to one side of the scan showing what resolution was used. What you really want is one colour change for at least every _ dioptre, meaning, for example, that 42.0 is green and 43.0 is yellow and there’s a few discernible shades in between. Obviously, the greater the resolution, the less information the scan will give you. If resolution is set too high, everything is going to look beautiful. If it is set lower, you actually have a chance of seeing useful information. (Remember when you had to decide between a 2.0 megapixel and a 3.0 megapixel digital camera.... well, this is a lot more important.)
Now, down to business.
I’m taking a big risk in talking about topographies. Why? On the one hand, I’m not an expert. On the other hand, I’ve been told a lot of nonsense by people who should be experts. On the other hand, one or two experts whose opinions I value think it’s complicated stuff and are sometimes hesitant to pronounce judgement on certain kinds of things. On the other hand, one or two other experts whose scientific honesty I value think it is almost as simple as it ought to be and that there are actually some reasonable rules you can apply. On the other hand, when one has seen piles of topographies of people with horrible optical results from LASIK, presumably one ought to be able to identify certain common aspects contributing to the horribleness of their results. On the other hand, one never seems to see post-operative topographies from people with anywhere from acceptable to good to excellent results, because they’re simply so happy their doctor never bothered, and one wonders whether, if nobody’s analysing good topos, how does one know what good topos ought to look like? On the other hand...
For heaven’s sakes, how many hands can a person be expected to count on? Topos, tapas. I’m tired of debating with myself and will simply take the leap.
So, I’m going to take a stab at one or two basic points, and hopefully wherever I am wrong or incomplete, the medical community will rise up in wrath and pummel me with excellent, user-friendly scientific studies showing me the error of my ways in which case I will hasten to revise this text. Incidentally, at the time of this writing a trusted MD friend is engaged in research on this very topic and I am impatiently awaiting the results so that I can get a clearer view on what makes for good topos.
1. You should be looking at something that looks vaguely like a blue circle in a sea of red, with the bluish part extending for a certain way (across at least a couple of the boxes in the grid) then giving way to a progression of colours working their way up the rainbow: green, yellow, and orange, then red.
2. You should be able to identify your functional optical zone in there somewhere. The functional optical zone is the part that has been given full refractive error correction by the laser. The functional optical zone should be close to, but then again may not be anywhere near, the planned ablation zone as indicated on the operative report. That was the plan. This is the reality. We know people with FOZs as small as 2.5mm where their laser was programmed for 5.5. A little bit of this can be due to what’s known as ablation shrinkage, but the rest must be attributed to either what the laser did, or how badly the cornea was bothered by what the laser did.
3. Really small FOZs are Bad Things.
4. FOZs that are not all that small but are still smaller than your pupil size in dim light or dark are also Bad Things.
5. If you can’t identify your FOZ at all because there are so many colours swimming around right in the centre of the ablation, that is a Bad Thing.
6. Now, look at that blue circle (if there is one) or at any rate the central 6mm of your cornea. If it’s reasonably round, that means it had a centre. Try to identify the centre.
7. If the centre of the blue circle is not somewhere very near to the centre of your pupil, that is a very Bad Thing.
8. If the centre of the blue circle is perfectly aligned with the centre of your pupil, but there is a little X indicating your line of sight and that’s kind of offset from your pupil, and you had a high prescription, that might be a Bad Thing. (There is an industry argument over whether the ablation should be centred on the pupil or centred on the line of sight. Kind of important, like, boys, we need to decide whether we’re aiming to wing him or get him right in the heart.
9. Now, look at the central 6mm of your topography, and forget about whether it’s all the same colour (it probably isn’t or you wouldn’t be here). Do you see anything that looks like a bow tie, or a bug splat, or islands swimming around? That might not be a good thing. Now use the key that shows what fraction of a dioptre is represented by a colour. Are any of those fancy things more than 0.5 dioptre different in colour than the stuff around them? That indicates a Bad Thing.
10. Looking at that same central 6mm, use the key and find the minimum and maximum number of dioptres within that circle, and add up the different colours. If you are seeing 3 or more colours, and the minimum and maximum are 1.00 dioptre or more apart from each other, those are Bad Things. You should not have to be looking out at the world through all different kinds of refractive powered cornea. You might still be able to read an eye chart especially if the 1mm at the centre of your cornea is just the right power, but that doesn’t help too much with real life.
11. If your pupil size in dim light is greater than 6mm (which is probably the case: it is statistically true for half the population, and since you’ve got a bad result from surgery, it’s rather more likely to be true of you) look at the area between 6mm and however large your pupil is in dim light, and apply rules 9 and 10, and see if you find any more Bad Things.
By now, you are getting the idea. You ought to have a reasonably nice looking lasered area on your cornea that goes out somewhere at least close to where your pupil’s going to extend to. If you don’t, nobody should be surprised that you have some significant vision disturbances. If you do, you may still have plenty of reasons for vision disturbances when we get down to the dirty details. You’ll have to stay tuned for when The Lone Dog starts talking about that.
Excimer Lasik
The excimer laser has been used in the past few years to correct myopia. There are several thousand people in the United States who have had excimer laser surgery through research studies that are authorized and reviewed by the Food and Drug Administration. The excimer laser is limited in the U.S. to investigation use only.
In a process called photorefracive keratectomy (PRK), the excimer laser precisely sculpts the surface of the cornea using invisible, high-energy light. While not yet proven, it is hoped that this procedure will produce more stable vision than RK.
No surgical blades are used. The surgery takes about 15 minutes using eye drops to anesthetize the cornea. Complications during the procedure itself are very rare.
For mild to moderate myopia, PRK and RK have similar results. The cornea should be able to withstand injury better after PRK than after RK.
A common but temporary problem after PRK is hazy vision. It usually improves after several months and, based on current clinical trials, rarely results in a permanent scarring of the cornea.
Over 70% of people report some haloes or glare after PRK, especially at night; these symptoms usually decrease over 3 to 6 months. As with RK, however, most people are pleased with the improvement in eye sight unaided by glasses or contact lenses following PRK.
The long-term results and safety of PRK are unknown until research trials are completed.
In a process called photorefracive keratectomy (PRK), the excimer laser precisely sculpts the surface of the cornea using invisible, high-energy light. While not yet proven, it is hoped that this procedure will produce more stable vision than RK.
No surgical blades are used. The surgery takes about 15 minutes using eye drops to anesthetize the cornea. Complications during the procedure itself are very rare.
For mild to moderate myopia, PRK and RK have similar results. The cornea should be able to withstand injury better after PRK than after RK.
A common but temporary problem after PRK is hazy vision. It usually improves after several months and, based on current clinical trials, rarely results in a permanent scarring of the cornea.
Over 70% of people report some haloes or glare after PRK, especially at night; these symptoms usually decrease over 3 to 6 months. As with RK, however, most people are pleased with the improvement in eye sight unaided by glasses or contact lenses following PRK.
The long-term results and safety of PRK are unknown until research trials are completed.
Wednesday, August 13, 2008
Laser Eye Surgery: Is It Worth Looking Into?
"After wearing contact lenses for 35 years, you can't imagine the freedom I felt," says Goldstein.
Goldstein underwent refractive eye surgery, an elective procedure intended to correct common eye disorders, known as refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision). Although there are several types of surgical techniques being performed today to correct refractive errors, laser refractive correction is fast becoming the most technologically advanced method available, according to the American Academy of Ophthalmology in San Francisco. Doctors say it allows for an unparalleled degree of precision and predictability.
"Laser surgery is the most exciting advancement in ophthalmology," says James J. Salz, M.D., clinical professor of ophthalmology at the University of Southern California in Los Angeles and the doctor who performed Goldstein's surgery. But surprisingly, he says, despite its sudden popularity, "only 20 percent of ophthalmologists in the United States today are trained in its operation."
The Food and Drug Administration first approved the excimer laser in October 1995 for correcting mild to moderate nearsightedness. With that approval, the agency also restricted use of the laser to practitioners trained both in laser refractive surgery and in the calibration and operation of the laser. Currently, the excimer laser has been approved for use in a procedure called photorefractive keratectomy (PRK), and, as of November 1998, for a procedure called laser in situ Keratomileusis (LASIK).
Precision Surgery
PRK is an outpatient procedure generally performed with local anesthetic eye drops. This type of refractive surgery gently reshapes the cornea by removing microscopic amounts of tissue from the outer surface with a cool, computer-controlled ultraviolet beam of light. The beam is so precise it can cut notches in a strand of human hair without breaking it, and each pulse can remove 39 millionths of an inch of tissue in 12 billionths of a second. The procedure itself takes only a few minutes, and patients are typically back to daily routines in one to three days.
Before the procedure begins, the patient's eye is measured to determine the degree of visual problem, and a map of the eye's surface is constructed. The required corneal change is calculated based on this information, and then entered into the laser's computer.
Since 1995, a limited number of laser systems has been approved by FDA to treat various refractive errors, both with PRK and LASIK.
According to FDA's Center for Devices and Radiological Health, clinical studies showed that about 5 percent of patients continued to always need glasses following PRK for distance, and up to 15 percent needed glasses occasionally, such as when driving. In addition, many patients experienced mild corneal haze following surgery, which is part of the normal healing process. The haze appeared to have little or no effect on final vision, and could only be seen by a doctor with a microscope. Some patients experienced glare and halos around lights. These conditions, however, diminished or disappeared in most patients in six months. For about 5 percent of patients, however, best-corrected vision without corrective lenses was slightly worse after surgery than before. In view of these findings, FDA and the Federal Trade Commission (which oversees advertising) issued a letter to the eye-care community in May 1996 warning that unrealistic advertising claims, such as "throw away your eyeglasses," and unsubstantiated claims about success rates could be misleading to consumers.
LASIK
LASIK is a more complex procedure than PRK. It is performed for all degrees of nearsightedness. The surgeon uses a knife called a microkeratome to cut a flap of corneal tissue, removes the targeted tissue beneath it with the laser, and then replaces the flap.
"With LASIK, the skill of the surgeon is important because he'll be making an incision," says Stephen Crawford, O.D., an optometrist practicing in Virginia, "compared to the PRK method where the machine does more of the work." Crawford urges people to find qualified, experienced doctors to perform this surgery. "You'll want someone who's done a number of LASIK procedures since this is a surgeon-dependent operation," he said.
According to Ken Taylor, O.D., vice president of Arthur D. Little, Inc., a technology and management consultant firm in Cambridge, Mass., "Last year, across the country, 40 to 45 percent of refractive surgeries performed by physicians were LASIK, which equates to approximately 80,000 procedures." Doctors not participating in clinical trials may choose to use the approved laser to perform LASIK procedures at their discretion, says Morris Waxler, Ph.D., chief of FDA's diagnostic and surgical devices section. But most uses are considered "off label" and are not regulated by FDA.
Ralph A. Rosenthal, M.D., director of FDA's division of ophthalmic devices, says, "The agency has ruled that individual physicians can perform LASIK under the general 'practice of medicine,' if it's in the patient's best interest."
Advantages of LASIK
Some doctors believe that LASIK is a suitable procedure for correcting the most severe refractive errors. They also say that there is generally a faster recovery time after LASIK than after PRK. In addition, LASIK patients can see well enough to drive immediately and have good vision within a week.
After studying the options, Goldstein first decided on the LASIK procedure, but was surprised to learn that her doctor advised against it.
"Initially, I wanted the quick recovery that LASIK offers," Goldstein says, "but the bottom line was, which surgery will give me the best results, and after considering everything, eventually we agreed on PRK."
James Salz is currently involved in an FDA-sanctioned clinical trial at Cedars-Sinai Medical Center in Los Angeles, which is now studying the laser system specifically for farsightedness (hyperopia) with astigmatism. Although routinely performing laser eye surgery, he still encourages a small percentage of his low to moderately nearsighted patients to undergo radial keratotomy, or RK, an earlier refractive correction procedure that does not require the excimer laser.
With RK, incisions are made in a "radial" pattern along the outer portion of the cornea using a hand-held blade. These incisions are designed to help flatten the curvature of the cornea, thereby allowing light rays entering the eye to properly focus on the retina. The number and length of the incisions determines the degree of correction attained.
"Typically, this is still a practiced procedure for select people with very small corrections of myopia," Salz says.
Conversely, Crawford says that although he will mention RK as an option to his patients considering eye surgery, he is not in favor of this method. He says studies indicate that incisions made during this procedure, which penetrate approximately 90 percent of the cornea, appear to weaken the structure of the eye. Also, once you've had RK done you can't repeat it or have PRK done.
"I think that patients should understand and consider all available options for correcting refractive errors," Crawford says, "but I would never recommend RK to anyone."
Is Laser Surgery for You?
For some, like Goldstein, laser surgery has been the ultimate freedom from the everyday hassles of contact lenses, and a second chance at having normal eyesight. But can everyone expect such dramatic results?
"The answer is no," says Rosenthal. "It's not a foolproof procedure and people need to know that some can end up with worse eyesight than before they went in."
Mary Ann Duke, M.D., a general ophthalmologist practicing in Potomac, Md., adds that there are other reasons why the expectations for laser surgery vary from person to person.
"People who are slow healers or who have ongoing medical conditions [such as glaucoma or diabetes] are not good candidates for laser surgery," she says. "That's why it's so important for patients to undergo a thorough examination with their doctor."
Poor candidates for this surgery also include those with uncontrolled vascular disease, autoimmune disease, or people with certain eye diseases involving the cornea or retina. Pregnant women should not have refractive surgery of any kind because the refraction of the eye may change during pregnancy.
Looking Ahead
At present, a number of other lasers for eye surgery are currently being tested in FDA-sanctioned studies to determine their safety and effectiveness. Investigational Device Exemptions (IDEs) filed with FDA allow for clinical studies involving the excimer laser and the correction of farsightedness. The IDE process is designed to investigate the safety and effectiveness of a device, or a new procedure with an already approved device, either to obtain information for publication or to generate the data needed to obtain marketing approval from FDA.
"If the refractive surgery center says the laser is approved by FDA, it probably is," Waxler concludes. "Still, it is wise for consumers to check that the device being used for their surgery is FDA-approved," he says, or that they make sure they are being treated with a laser that is under study in an FDA-sanctioned clinical trial.
During the first few weeks immediately following laser surgery, Goldstein says, "Every week I kept thinking, 'this is as good as it gets'?" Then, she discovered by the sixth week, as predicted by her surgeon, that her eyesight was noticeably better and eventually stabilized.
"I would tell others to be patient about their expected outcome," she advises. "Even though with LASIK you can expect quicker results, I'm happy with the choice of PRK." by Carol Lewis
Goldstein underwent refractive eye surgery, an elective procedure intended to correct common eye disorders, known as refractive errors, such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism (distorted vision). Although there are several types of surgical techniques being performed today to correct refractive errors, laser refractive correction is fast becoming the most technologically advanced method available, according to the American Academy of Ophthalmology in San Francisco. Doctors say it allows for an unparalleled degree of precision and predictability.
"Laser surgery is the most exciting advancement in ophthalmology," says James J. Salz, M.D., clinical professor of ophthalmology at the University of Southern California in Los Angeles and the doctor who performed Goldstein's surgery. But surprisingly, he says, despite its sudden popularity, "only 20 percent of ophthalmologists in the United States today are trained in its operation."
The Food and Drug Administration first approved the excimer laser in October 1995 for correcting mild to moderate nearsightedness. With that approval, the agency also restricted use of the laser to practitioners trained both in laser refractive surgery and in the calibration and operation of the laser. Currently, the excimer laser has been approved for use in a procedure called photorefractive keratectomy (PRK), and, as of November 1998, for a procedure called laser in situ Keratomileusis (LASIK).
Precision Surgery
PRK is an outpatient procedure generally performed with local anesthetic eye drops. This type of refractive surgery gently reshapes the cornea by removing microscopic amounts of tissue from the outer surface with a cool, computer-controlled ultraviolet beam of light. The beam is so precise it can cut notches in a strand of human hair without breaking it, and each pulse can remove 39 millionths of an inch of tissue in 12 billionths of a second. The procedure itself takes only a few minutes, and patients are typically back to daily routines in one to three days.
Before the procedure begins, the patient's eye is measured to determine the degree of visual problem, and a map of the eye's surface is constructed. The required corneal change is calculated based on this information, and then entered into the laser's computer.
Since 1995, a limited number of laser systems has been approved by FDA to treat various refractive errors, both with PRK and LASIK.
According to FDA's Center for Devices and Radiological Health, clinical studies showed that about 5 percent of patients continued to always need glasses following PRK for distance, and up to 15 percent needed glasses occasionally, such as when driving. In addition, many patients experienced mild corneal haze following surgery, which is part of the normal healing process. The haze appeared to have little or no effect on final vision, and could only be seen by a doctor with a microscope. Some patients experienced glare and halos around lights. These conditions, however, diminished or disappeared in most patients in six months. For about 5 percent of patients, however, best-corrected vision without corrective lenses was slightly worse after surgery than before. In view of these findings, FDA and the Federal Trade Commission (which oversees advertising) issued a letter to the eye-care community in May 1996 warning that unrealistic advertising claims, such as "throw away your eyeglasses," and unsubstantiated claims about success rates could be misleading to consumers.
LASIK
LASIK is a more complex procedure than PRK. It is performed for all degrees of nearsightedness. The surgeon uses a knife called a microkeratome to cut a flap of corneal tissue, removes the targeted tissue beneath it with the laser, and then replaces the flap.
"With LASIK, the skill of the surgeon is important because he'll be making an incision," says Stephen Crawford, O.D., an optometrist practicing in Virginia, "compared to the PRK method where the machine does more of the work." Crawford urges people to find qualified, experienced doctors to perform this surgery. "You'll want someone who's done a number of LASIK procedures since this is a surgeon-dependent operation," he said.
According to Ken Taylor, O.D., vice president of Arthur D. Little, Inc., a technology and management consultant firm in Cambridge, Mass., "Last year, across the country, 40 to 45 percent of refractive surgeries performed by physicians were LASIK, which equates to approximately 80,000 procedures." Doctors not participating in clinical trials may choose to use the approved laser to perform LASIK procedures at their discretion, says Morris Waxler, Ph.D., chief of FDA's diagnostic and surgical devices section. But most uses are considered "off label" and are not regulated by FDA.
Ralph A. Rosenthal, M.D., director of FDA's division of ophthalmic devices, says, "The agency has ruled that individual physicians can perform LASIK under the general 'practice of medicine,' if it's in the patient's best interest."
Advantages of LASIK
Some doctors believe that LASIK is a suitable procedure for correcting the most severe refractive errors. They also say that there is generally a faster recovery time after LASIK than after PRK. In addition, LASIK patients can see well enough to drive immediately and have good vision within a week.
After studying the options, Goldstein first decided on the LASIK procedure, but was surprised to learn that her doctor advised against it.
"Initially, I wanted the quick recovery that LASIK offers," Goldstein says, "but the bottom line was, which surgery will give me the best results, and after considering everything, eventually we agreed on PRK."
James Salz is currently involved in an FDA-sanctioned clinical trial at Cedars-Sinai Medical Center in Los Angeles, which is now studying the laser system specifically for farsightedness (hyperopia) with astigmatism. Although routinely performing laser eye surgery, he still encourages a small percentage of his low to moderately nearsighted patients to undergo radial keratotomy, or RK, an earlier refractive correction procedure that does not require the excimer laser.
With RK, incisions are made in a "radial" pattern along the outer portion of the cornea using a hand-held blade. These incisions are designed to help flatten the curvature of the cornea, thereby allowing light rays entering the eye to properly focus on the retina. The number and length of the incisions determines the degree of correction attained.
"Typically, this is still a practiced procedure for select people with very small corrections of myopia," Salz says.
Conversely, Crawford says that although he will mention RK as an option to his patients considering eye surgery, he is not in favor of this method. He says studies indicate that incisions made during this procedure, which penetrate approximately 90 percent of the cornea, appear to weaken the structure of the eye. Also, once you've had RK done you can't repeat it or have PRK done.
"I think that patients should understand and consider all available options for correcting refractive errors," Crawford says, "but I would never recommend RK to anyone."
Is Laser Surgery for You?
For some, like Goldstein, laser surgery has been the ultimate freedom from the everyday hassles of contact lenses, and a second chance at having normal eyesight. But can everyone expect such dramatic results?
"The answer is no," says Rosenthal. "It's not a foolproof procedure and people need to know that some can end up with worse eyesight than before they went in."
Mary Ann Duke, M.D., a general ophthalmologist practicing in Potomac, Md., adds that there are other reasons why the expectations for laser surgery vary from person to person.
"People who are slow healers or who have ongoing medical conditions [such as glaucoma or diabetes] are not good candidates for laser surgery," she says. "That's why it's so important for patients to undergo a thorough examination with their doctor."
Poor candidates for this surgery also include those with uncontrolled vascular disease, autoimmune disease, or people with certain eye diseases involving the cornea or retina. Pregnant women should not have refractive surgery of any kind because the refraction of the eye may change during pregnancy.
Looking Ahead
At present, a number of other lasers for eye surgery are currently being tested in FDA-sanctioned studies to determine their safety and effectiveness. Investigational Device Exemptions (IDEs) filed with FDA allow for clinical studies involving the excimer laser and the correction of farsightedness. The IDE process is designed to investigate the safety and effectiveness of a device, or a new procedure with an already approved device, either to obtain information for publication or to generate the data needed to obtain marketing approval from FDA.
"If the refractive surgery center says the laser is approved by FDA, it probably is," Waxler concludes. "Still, it is wise for consumers to check that the device being used for their surgery is FDA-approved," he says, or that they make sure they are being treated with a laser that is under study in an FDA-sanctioned clinical trial.
During the first few weeks immediately following laser surgery, Goldstein says, "Every week I kept thinking, 'this is as good as it gets'?" Then, she discovered by the sixth week, as predicted by her surgeon, that her eyesight was noticeably better and eventually stabilized.
"I would tell others to be patient about their expected outcome," she advises. "Even though with LASIK you can expect quicker results, I'm happy with the choice of PRK." by Carol Lewis
Eye Surgery in India
With the rising economy and increase of per capita income, the Indian Medical sector is at a rise. Medical tourism is India is a rising concept which is slowly and gradually getting very popular in the West. Patients are travelling from all over the world, specially developed countries, to India to get medical treatment. Why ? The advantages include five-star facilities, high quality doctors, very low costs (almost 1/3rd as compared to the developed countries and in most cases, even lower) and finally, a great tourist destination.
A recent study by McKinsey estimated that India's medical tourism industry could yield as much as $2.2 billion in annual revenue by 2012. Airport pick-up & drop, visa assistance, interpreter services, sight seeing, arranging forex services - hospitals are here to service the patients from the west in full energy.
Eye surgery in India is one of the highly growing sectors in medical tourism. Several hospitals and clinics are now fully equipped to handle the inflow of patients from the West with latest technology, highly trained doctors and of course, customized treatment for every patient.
A recent study by McKinsey estimated that India's medical tourism industry could yield as much as $2.2 billion in annual revenue by 2012. Airport pick-up & drop, visa assistance, interpreter services, sight seeing, arranging forex services - hospitals are here to service the patients from the west in full energy.
Eye surgery in India is one of the highly growing sectors in medical tourism. Several hospitals and clinics are now fully equipped to handle the inflow of patients from the West with latest technology, highly trained doctors and of course, customized treatment for every patient.
Laser surgery fast becoming an alternative to eyewear
Eyewear is big business in the United States. Fifty-five percent of Americans regularly wear some form of corrective glasses or contact lenses, shelling out a total of $16 billion a year.
That trend may soon change as a small but growing number of people choose to correct their vision with laser surgery.
This year, an estimated 300,000 people will undergo undergo one on the main two types of laser surgery -- PRK and LASIK -- at an average cost of $2,100-$2,500 per eye.
Although laser eye surgery is considered cosmetic and is rarely covered by insurers, the procedure is fast becoming a popular alternative to eyewear, especially among those fed up with the daily ritual of wearing contact lenses.
"I didn't think about is as an economic decision, for me it was more lifestyle," said laser surgery patient Steven Kornblau, who was considered legally blind without his contact lenses.
Kornblau had LASIK (laser in-situ keratomileusis) surgery, the more complex of the two procedures performed on all degrees of nearsightedness. Under the LASIK procedure, a surgeon uses a knife called a microkeratome to cut into the corneal tissue and then removes the targeted tissue using lasers.
PRK (photorefractive keratectomy) is less invasive and used to correct minor problems. The patient is given local anesthetic eye drops before the surgeon gently reshapes the cornea with a cool, ultraviolet beam of light.
Although PRK surgery is less complicated, doctors warn that both procedures include risks -- ranging from infections to night-vision glare -- and don't guarantee perfect vision.
"Some patients have pretty good vision without correction afterward, but still might need glasses for night driving or something like that. Generally, these procedures do not eliminate the need for reading glasses when you are in your late '40s or early '50s," said Dr. Karla Zadnik of the Ohio State College of Optometry.
That trend may soon change as a small but growing number of people choose to correct their vision with laser surgery.
This year, an estimated 300,000 people will undergo undergo one on the main two types of laser surgery -- PRK and LASIK -- at an average cost of $2,100-$2,500 per eye.
Although laser eye surgery is considered cosmetic and is rarely covered by insurers, the procedure is fast becoming a popular alternative to eyewear, especially among those fed up with the daily ritual of wearing contact lenses.
"I didn't think about is as an economic decision, for me it was more lifestyle," said laser surgery patient Steven Kornblau, who was considered legally blind without his contact lenses.
Kornblau had LASIK (laser in-situ keratomileusis) surgery, the more complex of the two procedures performed on all degrees of nearsightedness. Under the LASIK procedure, a surgeon uses a knife called a microkeratome to cut into the corneal tissue and then removes the targeted tissue using lasers.
PRK (photorefractive keratectomy) is less invasive and used to correct minor problems. The patient is given local anesthetic eye drops before the surgeon gently reshapes the cornea with a cool, ultraviolet beam of light.
Although PRK surgery is less complicated, doctors warn that both procedures include risks -- ranging from infections to night-vision glare -- and don't guarantee perfect vision.
"Some patients have pretty good vision without correction afterward, but still might need glasses for night driving or something like that. Generally, these procedures do not eliminate the need for reading glasses when you are in your late '40s or early '50s," said Dr. Karla Zadnik of the Ohio State College of Optometry.
Tuesday, August 12, 2008
Some Risk Factors Dealing with Eye?
Most patients are very pleased with the results of their refractive surgery. However, like any other medical procedure, there are risks involved. That's why it is important for you to understand the limitations and possible complications of refractive surgery.
Before undergoing a refractive procedure, you should carefully weigh the risks and benefits based on your own personal value system, and try to avoid being influenced by friends that have had the procedure or doctors encouraging you to do so.
* Some patients lose vision. Some patients lose lines of vision on the vision chart that cannot be corrected with glasses, contact lenses, or surgery as a result of treatment.
* Some patients develop debilitating visual symptoms. Some patients develop glare, halos, and/or double vision that can seriously affect nighttime vision. Even with good vision on the vision chart, some patients do not see as well in situations of low contrast, such as at night or in fog, after treatment as compared to before treatment.
* You may be under treated or over treated. Only a certain percent of patients achieve 20/20 vision without glasses or contacts. You may require additional treatment, but additional treatment may not be possible. You may still need glasses or contact lenses after surgery. This may be true even if you only required a very weak prescription before surgery. If you used reading glasses before surgery, you may still need reading glasses after surgery.
* Some patients may develop severe dry eye syndrome. As a result of surgery, your eye may not be able to produce enough tears to keep the eye moist and comfortable. Dry eye not only causes discomfort, but can reduce visual quality due to intermittent blurring and other visual symptoms. This condition may be permanent. Intensive drop therapy and use of plugs or other procedures may be required.
* Results are generally not as good in patients with very large refractive errors of any type. You should discuss your expectations with your doctor and realize that you may still require glasses or contacts after the surgery.
* For some farsighted patients, results may diminish with age. If you are farsighted, the level of improved vision you experience after surgery may decrease with age. This can occur if your manifest refraction (a vision exam with lenses before dilating drops) is very different from your cycloplegic refraction (a vision exam with lenses after dilating drops).
* Long-term data are not available. LASIK is a relatively new technology. The first laser was approved for LASIK eye surgery in 1998. Therefore, the long-term safety and effectiveness of LASIK surgery is not known.
Additional Risks if you are Considering the Following:
* Monovision
Monovision is one clinical technique used to deal with the correction of presbyopia, the gradual loss of the ability of the eye to change focus for close-up tasks that progresses with age. The intent of monovision is for the presbyopic patient to use one eye for distance viewing and one eye for near viewing. This practice was first applied to fit contact lens wearers and more recently to LASIK and other refractive surgeries. With contact lenses, a presbyopic patient has one eye fit with a contact lens to correct distance vision, and the other eye fit with a contact lens to correct near vision. In the same way, with LASIK, a presbyopic patient has one eye operated on to correct the distance vision, and the other operated on to correct the near vision. In other words, the goal of the surgery is for one eye to have vision worse than 20/20, the commonly referred to goal for LASIK surgical correction of distance vision. Since one eye is corrected for distance viewing and the other eye is corrected for near viewing, the two eyes no longer work together. This results in poorer quality vision and a decrease in depth perception. These effects of monovision are most noticeable in low lighting conditions and when performing tasks requiring very sharp vision. Therefore, you may need to wear glasses or contact lenses to fully correct both eyes for distance or near when performing visually demanding tasks, such as driving at night, operating dangerous equipment, or performing occupational tasks requiring very sharp close vision (e.g., reading small print for long periods of time).
Many patients cannot get used to having one eye blurred at all times. Therefore, if you are considering monovision with LASIK, make sure you go through a trial period with contact lenses to see if you can tolerate monovision, before having the surgery performed on your eyes. Find out if you pass your state's driver's license requirements with monovision.
In addition, you should consider how much your presbyopia is expected to increase in the future. Ask your doctor when you should expect the results of your monovision surgery to no longer be enough for you to see near-by objects clearly without the aid of glasses or contacts, or when a second surgery might be required to further correct your near vision.
* Bilateral Simultaneous Treatment
You may choose to have LASIK surgery on both eyes at the same time or to have surgery on one eye at a time. Although the convenience of having surgery on both eyes on the same day is attractive, this practice is riskier than having two separate surgeries.
If you decide to have one eye done at a time, you and your doctor will decide how long to wait before having surgery on the other eye. If both eyes are treated at the same time or before one eye has a chance to fully heal, you and your doctor do not have the advantage of being able to see how the first eye responds to surgery before the second eye is treated.
Another disadvantage to having surgery on both eyes at the same time is that the vision in both eyes may be blurred after surgery until the initial healing process is over, rather than being able to rely on clear vision in at least one eye at all times.
Finding the Right Doctor
If you are considering refractive surgery, make sure you:
* Compare. The levels of risk and benefit vary slightly not only from procedure to procedure, but from device to device depending on the manufacturer, and from surgeon to surgeon depending on their level of experience with a particular procedure.
* Don't base your decision simply on cost and don't settle for the first eye center, doctor, or procedure you investigate. Remember that the decisions you make about your eyes and refractive surgery will affect you for the rest of your life.
* Be wary of eye centers that advertise, "20/20 vision or your money back" or "package deals." There are never any guarantees in medicine.
* Read. It is important for you to read the patient handbook provided to your doctor by the manufacturer of the device used to perform the refractive procedure. Your doctor should provide you with this handbook and be willing to discuss his/her outcomes (successes as well as complications) compared to the results of studies outlined in the handbook.
Even the best screened patients under the care of most skilled surgeons can experience serious complications.
* During surgery. Malfunction of a device or other error, such as cutting a flap of cornea through and through instead of making a hinge during LASIK surgery, may lead to discontinuation of the procedure or irreversible damage to the eye.
* After surgery. Some complications, such as migration of the flap, inflammation or infection, may require another procedure and/or intensive treatment with drops. Even with aggressive therapy, such complications may lead to temporary loss of vision or even irreversible blindness.
Under the care of an experienced doctor, carefully screened candidates with reasonable expectations and a clear understanding of the risks and alternatives are likely to be happy with the results of their refractive procedure.
Before undergoing a refractive procedure, you should carefully weigh the risks and benefits based on your own personal value system, and try to avoid being influenced by friends that have had the procedure or doctors encouraging you to do so.
* Some patients lose vision. Some patients lose lines of vision on the vision chart that cannot be corrected with glasses, contact lenses, or surgery as a result of treatment.
* Some patients develop debilitating visual symptoms. Some patients develop glare, halos, and/or double vision that can seriously affect nighttime vision. Even with good vision on the vision chart, some patients do not see as well in situations of low contrast, such as at night or in fog, after treatment as compared to before treatment.
* You may be under treated or over treated. Only a certain percent of patients achieve 20/20 vision without glasses or contacts. You may require additional treatment, but additional treatment may not be possible. You may still need glasses or contact lenses after surgery. This may be true even if you only required a very weak prescription before surgery. If you used reading glasses before surgery, you may still need reading glasses after surgery.
* Some patients may develop severe dry eye syndrome. As a result of surgery, your eye may not be able to produce enough tears to keep the eye moist and comfortable. Dry eye not only causes discomfort, but can reduce visual quality due to intermittent blurring and other visual symptoms. This condition may be permanent. Intensive drop therapy and use of plugs or other procedures may be required.
* Results are generally not as good in patients with very large refractive errors of any type. You should discuss your expectations with your doctor and realize that you may still require glasses or contacts after the surgery.
* For some farsighted patients, results may diminish with age. If you are farsighted, the level of improved vision you experience after surgery may decrease with age. This can occur if your manifest refraction (a vision exam with lenses before dilating drops) is very different from your cycloplegic refraction (a vision exam with lenses after dilating drops).
* Long-term data are not available. LASIK is a relatively new technology. The first laser was approved for LASIK eye surgery in 1998. Therefore, the long-term safety and effectiveness of LASIK surgery is not known.
Additional Risks if you are Considering the Following:
* Monovision
Monovision is one clinical technique used to deal with the correction of presbyopia, the gradual loss of the ability of the eye to change focus for close-up tasks that progresses with age. The intent of monovision is for the presbyopic patient to use one eye for distance viewing and one eye for near viewing. This practice was first applied to fit contact lens wearers and more recently to LASIK and other refractive surgeries. With contact lenses, a presbyopic patient has one eye fit with a contact lens to correct distance vision, and the other eye fit with a contact lens to correct near vision. In the same way, with LASIK, a presbyopic patient has one eye operated on to correct the distance vision, and the other operated on to correct the near vision. In other words, the goal of the surgery is for one eye to have vision worse than 20/20, the commonly referred to goal for LASIK surgical correction of distance vision. Since one eye is corrected for distance viewing and the other eye is corrected for near viewing, the two eyes no longer work together. This results in poorer quality vision and a decrease in depth perception. These effects of monovision are most noticeable in low lighting conditions and when performing tasks requiring very sharp vision. Therefore, you may need to wear glasses or contact lenses to fully correct both eyes for distance or near when performing visually demanding tasks, such as driving at night, operating dangerous equipment, or performing occupational tasks requiring very sharp close vision (e.g., reading small print for long periods of time).
Many patients cannot get used to having one eye blurred at all times. Therefore, if you are considering monovision with LASIK, make sure you go through a trial period with contact lenses to see if you can tolerate monovision, before having the surgery performed on your eyes. Find out if you pass your state's driver's license requirements with monovision.
In addition, you should consider how much your presbyopia is expected to increase in the future. Ask your doctor when you should expect the results of your monovision surgery to no longer be enough for you to see near-by objects clearly without the aid of glasses or contacts, or when a second surgery might be required to further correct your near vision.
* Bilateral Simultaneous Treatment
You may choose to have LASIK surgery on both eyes at the same time or to have surgery on one eye at a time. Although the convenience of having surgery on both eyes on the same day is attractive, this practice is riskier than having two separate surgeries.
If you decide to have one eye done at a time, you and your doctor will decide how long to wait before having surgery on the other eye. If both eyes are treated at the same time or before one eye has a chance to fully heal, you and your doctor do not have the advantage of being able to see how the first eye responds to surgery before the second eye is treated.
Another disadvantage to having surgery on both eyes at the same time is that the vision in both eyes may be blurred after surgery until the initial healing process is over, rather than being able to rely on clear vision in at least one eye at all times.
Finding the Right Doctor
If you are considering refractive surgery, make sure you:
* Compare. The levels of risk and benefit vary slightly not only from procedure to procedure, but from device to device depending on the manufacturer, and from surgeon to surgeon depending on their level of experience with a particular procedure.
* Don't base your decision simply on cost and don't settle for the first eye center, doctor, or procedure you investigate. Remember that the decisions you make about your eyes and refractive surgery will affect you for the rest of your life.
* Be wary of eye centers that advertise, "20/20 vision or your money back" or "package deals." There are never any guarantees in medicine.
* Read. It is important for you to read the patient handbook provided to your doctor by the manufacturer of the device used to perform the refractive procedure. Your doctor should provide you with this handbook and be willing to discuss his/her outcomes (successes as well as complications) compared to the results of studies outlined in the handbook.
Even the best screened patients under the care of most skilled surgeons can experience serious complications.
* During surgery. Malfunction of a device or other error, such as cutting a flap of cornea through and through instead of making a hinge during LASIK surgery, may lead to discontinuation of the procedure or irreversible damage to the eye.
* After surgery. Some complications, such as migration of the flap, inflammation or infection, may require another procedure and/or intensive treatment with drops. Even with aggressive therapy, such complications may lead to temporary loss of vision or even irreversible blindness.
Under the care of an experienced doctor, carefully screened candidates with reasonable expectations and a clear understanding of the risks and alternatives are likely to be happy with the results of their refractive procedure.
Laser Thermal Keratoplasty
Laser Thermal Keratoplasty (LTK) uses the holmium YAG laser to heat the tissue of the cornea, causing it to shrink and steepen the front of the eye to change the focus of incoming light onto the retina, the light-sensitive layer of tissue at the back of the eye. The goal of LTK is to improve the patient’s ability to see objects at a distance. It is unsure how long LTK results will last. When the US Food and Drug Administration approved LTK in the summer of 2000, it was originally labeled a “temporary” treatment. But some studies indicate could work longer than initially believed and the FDA has removed the word temporary. The laser device was approved to be used to treat patients who have farsightedness (between +0.75 to +2.5 diopters ), who are at least 40 years of age, and whose visual acuity has changed very little over time (that is, the patient’s glasses prescription has changed no more than 0.50 diopter in the previous six months.)
According to the FDA, this treatment may improve distance vision in far-sighted people who have difficulty seeing clearly at a distance. Although some patients may retain some or all of the correction achieved during the surgery, for most people the amount of farsightedness correction achieved will decrease over time. The amount of correction remaining at 24 months is typically about half of the correction observed at 6 months. Some patients will regress completely. How long any significant portion of the correction lasts depends on the amount of correction attempted and age.
According to the FDA, this treatment may improve distance vision in far-sighted people who have difficulty seeing clearly at a distance. Although some patients may retain some or all of the correction achieved during the surgery, for most people the amount of farsightedness correction achieved will decrease over time. The amount of correction remaining at 24 months is typically about half of the correction observed at 6 months. Some patients will regress completely. How long any significant portion of the correction lasts depends on the amount of correction attempted and age.
Surgery May Prevent "Lazy Eye" Blindness
Dr. Paul Dougherty delicately slipped a tiny lens inside the right eye of 7-year-old Megan Garvin - a last-ditch shot at saving her sight in that eye.
The California girl last week became one of a small number of United States children to have an experimental surgery to prevent virtual blindness from "lazy eye" diagnosed too late, or too severe, for standard treatment.
The new approach: Implantable lenses, the same kind that nearsighted adults can have inserted for crisper vision - but that aren't officially approved for use in children.
"Without this technology, we couldn't help her," says Dougherty, a prominent Los Angeles eye surgeon who invited The Associated Press to document Megan's surgery. "This would be written off as a blind eye."
Up to five percent of children have amblyopia, commonly called lazy eye, where one eye is so much stronger than the other that the brain learns to ignore the weaker eye. Untreated, the proper neural connections for vision don't form, eventually rendering that eye useless.
Catch it early - preferably by preschool - and it can be fairly easy to fix by patching over the strong eye, or using special drops in it, for several hours a day so that the brain is forced to use the weak eye. But the older the child is, the less effective the treatment - and by age nine, brain-eye connections are pretty well set.
The leading cause is eyes that aren't in perfect alignment. But a big difference in focusing power also triggers amblyopia. That's what happened with the Garvin girl, who had near-perfect vision in one eye but the other was too nearsighted to even see the big E on the eye chart.
It's sneaky: Kids don't realize they're seeing clearly out of only one eye, and often won't squint or otherwise signal there's a problem. So Megan was fast passing the window to correct amblyopia when a kindergarten eye exam flagged a problem.
"She reads perfectly, she's a very normal active child," says her mother, Rosie Garvin. "If she would not have had that vision test, I would never have known."
"We went in," Rosie told CBS News, "and they had her cover the one eye, and she did just fine. And then, when they covered the other eye, it was shocking. ... I think anytime that you find something is wrong, or not normal, it's devastating."
Ophthalmologists called it one of the worst cases they'd ever seen.
Glasses weren't do-able: One side would have required a clear lens and the other a Coke-bottle thickness, a prescription of minus-12 diopters.
Her parents tried inserting a contact lens in the bad eye -- getting her to roughly 20-60 vision in that eye, far from perfect, but able to see blurrily while the good eye was patched.
Contacts and young kids are a tough match. Megan cried when her mother inserted it. Teachers would call to say it had popped out.
Frustrated, the Garvins ultimately opted for the implant - and days later, are feeling hopeful. It's blurry, Megan tells her mother, but she can see out of her right eye, and is chafing at the required week of rest to let the tiny incisions in her eye heal.
That's just the first step. Months of patching lie ahead to try to reverse the lazy eye, or the brain would just stick with the connections it has already formed to her strong eye. Dougherty gave no guarantees.
"I know we've got our work ahead of us," says Rosie Garvin, from Simi Valley, Calif. "I'm so relieved ... and going to make sure I do everything they tell me to make sure this works for her for life."
"She's gotta live with the decision that her mom and dad made for her when she was seven years old," Rosie observed to CBS News, "and we're just hoping that we've made the right decision -- that this is something that will be a long-term benefit for her."
Dougherty told CBS News Megan is the first girl to have the procedure in the U.S.
He explained that the lens is rolled up "like a taco" when it's inserted, then it's allowed to unfurl, and winds up flat, covering the iris (colored part of the eye).
Implantable lenses for adults, called phakic intraocular lenses or IOLs, hit the U.S. market in 2004. Unlike cataract surgery, which requires removal of the eye's natural lens because it is clouded, these lenses are put on top of a natural lens that can't focus properly, thus helping sharpen vision.
They have some risks: Surgical infection, inflammation, a potential for cataracts to form. At about $4,000 an eye, it's more expensive than the controversial laser eye surgery LASIK, but the lenses can be removed if there are problems.
But, "How this lens is going to work in a child's eye, we don't know. We've never done studies," cautions Dr. Punin Shah, a cornea specialist at Ochsner Medical Center in New Orleans.
It is legal to implant the lenses experimentally in a child, however.
A handful of medical journal reports show surgeons are starting to try the approach for hard-to-treat amblyopia. In a French study of a dozen children, all had improved vision after the surgery and half recovered normal binocular vision.
Other surgeons are experimenting with LASIK in children like Megan, although she wasn't a LASIK candidate - her corneas were too thin for it to be done safely, and Dougherty says it doesn't work well for such severe nearsightedness.
Dr. Michael Repka, a pediatric ophthalmologist at Baltimore's Johns Hopkins University, says both approaches are in their infancy, but interesting.
"It's an exciting thing in a patient who has had conventional therapy and failed," says Repka, a spokesman for the American Academy of Ophthalmology.
And while catching lazy eye very young is best, stay tuned: Repka's own research shows it can be possible to treat after age nine, long the cut-off, and he is to publish details soon.
The California girl last week became one of a small number of United States children to have an experimental surgery to prevent virtual blindness from "lazy eye" diagnosed too late, or too severe, for standard treatment.
The new approach: Implantable lenses, the same kind that nearsighted adults can have inserted for crisper vision - but that aren't officially approved for use in children.
"Without this technology, we couldn't help her," says Dougherty, a prominent Los Angeles eye surgeon who invited The Associated Press to document Megan's surgery. "This would be written off as a blind eye."
Up to five percent of children have amblyopia, commonly called lazy eye, where one eye is so much stronger than the other that the brain learns to ignore the weaker eye. Untreated, the proper neural connections for vision don't form, eventually rendering that eye useless.
Catch it early - preferably by preschool - and it can be fairly easy to fix by patching over the strong eye, or using special drops in it, for several hours a day so that the brain is forced to use the weak eye. But the older the child is, the less effective the treatment - and by age nine, brain-eye connections are pretty well set.
The leading cause is eyes that aren't in perfect alignment. But a big difference in focusing power also triggers amblyopia. That's what happened with the Garvin girl, who had near-perfect vision in one eye but the other was too nearsighted to even see the big E on the eye chart.
It's sneaky: Kids don't realize they're seeing clearly out of only one eye, and often won't squint or otherwise signal there's a problem. So Megan was fast passing the window to correct amblyopia when a kindergarten eye exam flagged a problem.
"She reads perfectly, she's a very normal active child," says her mother, Rosie Garvin. "If she would not have had that vision test, I would never have known."
"We went in," Rosie told CBS News, "and they had her cover the one eye, and she did just fine. And then, when they covered the other eye, it was shocking. ... I think anytime that you find something is wrong, or not normal, it's devastating."
Ophthalmologists called it one of the worst cases they'd ever seen.
Glasses weren't do-able: One side would have required a clear lens and the other a Coke-bottle thickness, a prescription of minus-12 diopters.
Her parents tried inserting a contact lens in the bad eye -- getting her to roughly 20-60 vision in that eye, far from perfect, but able to see blurrily while the good eye was patched.
Contacts and young kids are a tough match. Megan cried when her mother inserted it. Teachers would call to say it had popped out.
Frustrated, the Garvins ultimately opted for the implant - and days later, are feeling hopeful. It's blurry, Megan tells her mother, but she can see out of her right eye, and is chafing at the required week of rest to let the tiny incisions in her eye heal.
That's just the first step. Months of patching lie ahead to try to reverse the lazy eye, or the brain would just stick with the connections it has already formed to her strong eye. Dougherty gave no guarantees.
"I know we've got our work ahead of us," says Rosie Garvin, from Simi Valley, Calif. "I'm so relieved ... and going to make sure I do everything they tell me to make sure this works for her for life."
"She's gotta live with the decision that her mom and dad made for her when she was seven years old," Rosie observed to CBS News, "and we're just hoping that we've made the right decision -- that this is something that will be a long-term benefit for her."
Dougherty told CBS News Megan is the first girl to have the procedure in the U.S.
He explained that the lens is rolled up "like a taco" when it's inserted, then it's allowed to unfurl, and winds up flat, covering the iris (colored part of the eye).
Implantable lenses for adults, called phakic intraocular lenses or IOLs, hit the U.S. market in 2004. Unlike cataract surgery, which requires removal of the eye's natural lens because it is clouded, these lenses are put on top of a natural lens that can't focus properly, thus helping sharpen vision.
They have some risks: Surgical infection, inflammation, a potential for cataracts to form. At about $4,000 an eye, it's more expensive than the controversial laser eye surgery LASIK, but the lenses can be removed if there are problems.
But, "How this lens is going to work in a child's eye, we don't know. We've never done studies," cautions Dr. Punin Shah, a cornea specialist at Ochsner Medical Center in New Orleans.
It is legal to implant the lenses experimentally in a child, however.
A handful of medical journal reports show surgeons are starting to try the approach for hard-to-treat amblyopia. In a French study of a dozen children, all had improved vision after the surgery and half recovered normal binocular vision.
Other surgeons are experimenting with LASIK in children like Megan, although she wasn't a LASIK candidate - her corneas were too thin for it to be done safely, and Dougherty says it doesn't work well for such severe nearsightedness.
Dr. Michael Repka, a pediatric ophthalmologist at Baltimore's Johns Hopkins University, says both approaches are in their infancy, but interesting.
"It's an exciting thing in a patient who has had conventional therapy and failed," says Repka, a spokesman for the American Academy of Ophthalmology.
And while catching lazy eye very young is best, stay tuned: Repka's own research shows it can be possible to treat after age nine, long the cut-off, and he is to publish details soon.
Permanent Vision Correction Now Available at Angelo Laser Eye Center
A new opportunity for permanent vision correction now available at Angelo Laser Eye Center is allowing patients who before had no other options the freedom to see without glasses or contact lenses. The procedure allows for the permanent implantation of contact lenses within the eye, and it is seeing some remarkable results.
“I have been performing vision correction procedures for more than 12 years, but I am excited to now be able to offer implantable contact lenses to our area,” said Daniel Wilson, M.D., ophthalmologist at Shannon Clinic and Angelo Laser Eye Center. “It gives new hope to patients who previously had no other solution. They can now enjoy life and go to the beach or swim without having to worry about glasses or contacts.”
Dr. Wilson is the first and only ophthalmologist to offer the new implantable lenses in this part of the Concho Valley. Although it has been performed successfully worldwide for more than 15 years, the FDA approved it in the U.S. just about a year ago.
“There are some individuals who cannot have LASIK or other vision correction procedures because they are either too nearsighted, their corneas are thinner than normal, or their corneas have an abnormal shape.”
Dr. Wilson adds that most patients pursuing the procedure have vision that is worse than 20/1000 before surgery.
The thin, pliable lenses are made from Collamer, which is an organic protein material containing collagen, so they are easily accepted by the body. They are invisible and undetectable
“The lenses actually give better sight than traditional contact lenses or LASIK surgery,” said Dr. Wilson. “They are maintenance free since they are not on the surface of the eye and also reduce the risk of infection that traditional contacts can introduce to the eye.”
For individuals interested in the procedure, Dr. Wilson first sets up an initial consultation to examine their eyes and ensure they are a good candidate for the procedure.
“We do several things in that first visit including a specular microscopy test where we measure and count the cells on the back or inside layer of the cornea to be sure it is healthy and functional. We also look inside the eye with special technology called gonioscopy to be sure there is adequate space for the implantable lens.”
The outpatient procedure for inserting the lenses takes less than 30 minutes and is similar to cataract surgery except it does not require removing the eye’s natural lens. The patient remains awake, the eye is numbed with a topical or local anesthetic, and a mild sedative may be given if necessary. An opening, just three millimeters wide is made in the cornea, and the implantable lens is inserted placed behind the iris and in front of the natural lens. The opening is self healing and does not require stitches.
“The patient’s vision is checked two hours later, and at that time, most patients can already pass their driver’s test,” said Dr. Wilson.
Patients are able to return to work the following day, and use prescribed eye drops for about three weeks afterward. Patients heal fully within a month.
Although the lenses are intended to be permanent, they are removable and can be changed later if needed. And unlike other corrective vision procedures, there is no alteration to the cornea.
“The procedure is very quick, safe, and effective, and I hope it will be able to help many individuals and enhance their lives,” said Dr. Wilson.
To learn more about implantable contact lenses, call the Angelo Laser Eye Center at (325) 481-2020.
“I have been performing vision correction procedures for more than 12 years, but I am excited to now be able to offer implantable contact lenses to our area,” said Daniel Wilson, M.D., ophthalmologist at Shannon Clinic and Angelo Laser Eye Center. “It gives new hope to patients who previously had no other solution. They can now enjoy life and go to the beach or swim without having to worry about glasses or contacts.”
Dr. Wilson is the first and only ophthalmologist to offer the new implantable lenses in this part of the Concho Valley. Although it has been performed successfully worldwide for more than 15 years, the FDA approved it in the U.S. just about a year ago.
“There are some individuals who cannot have LASIK or other vision correction procedures because they are either too nearsighted, their corneas are thinner than normal, or their corneas have an abnormal shape.”
Dr. Wilson adds that most patients pursuing the procedure have vision that is worse than 20/1000 before surgery.
The thin, pliable lenses are made from Collamer, which is an organic protein material containing collagen, so they are easily accepted by the body. They are invisible and undetectable
“The lenses actually give better sight than traditional contact lenses or LASIK surgery,” said Dr. Wilson. “They are maintenance free since they are not on the surface of the eye and also reduce the risk of infection that traditional contacts can introduce to the eye.”
For individuals interested in the procedure, Dr. Wilson first sets up an initial consultation to examine their eyes and ensure they are a good candidate for the procedure.
“We do several things in that first visit including a specular microscopy test where we measure and count the cells on the back or inside layer of the cornea to be sure it is healthy and functional. We also look inside the eye with special technology called gonioscopy to be sure there is adequate space for the implantable lens.”
The outpatient procedure for inserting the lenses takes less than 30 minutes and is similar to cataract surgery except it does not require removing the eye’s natural lens. The patient remains awake, the eye is numbed with a topical or local anesthetic, and a mild sedative may be given if necessary. An opening, just three millimeters wide is made in the cornea, and the implantable lens is inserted placed behind the iris and in front of the natural lens. The opening is self healing and does not require stitches.
“The patient’s vision is checked two hours later, and at that time, most patients can already pass their driver’s test,” said Dr. Wilson.
Patients are able to return to work the following day, and use prescribed eye drops for about three weeks afterward. Patients heal fully within a month.
Although the lenses are intended to be permanent, they are removable and can be changed later if needed. And unlike other corrective vision procedures, there is no alteration to the cornea.
“The procedure is very quick, safe, and effective, and I hope it will be able to help many individuals and enhance their lives,” said Dr. Wilson.
To learn more about implantable contact lenses, call the Angelo Laser Eye Center at (325) 481-2020.
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