(Photo Refractive Keratectomy)
Benefits:
* Bowman's layer is spared.
* No removal of the corneal surface tissue is necessary and therefore post-operative pain is substantially reduced.
* Post-operative visual acuity is restored within a few days rather than weeks.
* Less corneal scarring in the long term, less change due to healing (regression) and thus greater stability of the correction.
When comparing only the benefits of Lasik over PRK the first impression is that Lasik has the potential to be a superior procedure. There is however, a very significant list of potential complications or risks and these include:
* Failure of automated instrument to leave a hinge on the corneal flap, with the first incision.
* Loss of the corneal flap during the operation.
* Loss of the corneal flap after the operation.
* Slipping of the flap and healing off center.
* First incision too deep (perforation of the eye) or too shallow, causing a hole in the flap.
* Invasion of the surface tissue into the central tissue of the cornea.
* Infection of the cornea.
* Loss of visual acuity - from scarring or from decentration of the PRK.
* Technical problems with complex and finicky automated diamond cutting devices.
* The procedure is much more dependent upon surgeon's operating skills, than the computerized precision of the PRK procedure.
The overall complication rate for the ALK-E or LASIK in Febuary 1995 was still in the order of 10% in the hands of the world leading innovators in the technique.
Friday, November 6, 2009
Laser Manufacturers
Aesculapx- Meditec GMBH
MEL 60- This is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is rectangular and measures 1mm by 10 mm. The system uses a limbal suction cup mechanism to fix centration and computer controlled rotating masks which fit into the suction cup mechanism. The mask for simple myopia is an f-stop like mechanism. There are different masks used for myopia with astigmatism, hyperopia, and for pure astigmatism. The masks rotate within the suction cup in order to control any axis of extra ablation as needed for astigmatism correction. Laser calibration is done by visual inspection of a 1um thick metal foil which requires 9 laser passes for removal. There is a layer of red under the silver foil making efficacy of removal easily monitored. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
ALCON
LADARVision® System and CustomCornea® - The LADARVision® System consists of the LADARVision® 4000 laser and the LADARWave® Aberrometer. The LADARVision excimer laser is a small-spot scanning laser with a laser radar tracking device. FDA approved for wavefront-guided ablations.
Bausch & Lomb Technolas 217 Excimer Laser with PLANOSCAN
Technolas 217 Workstation - this is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is a circular spot which can be size adjusted. Centration is accomplished by an active "pupil" tracking mechanism which locks on to the pupil image and will have the laser follow any movement by the patient's eye. Active Infra-red Eye Tracker and passive monitor interrupts laser beam on movement in excess of 3 mm range (1.5 mm radius). Astigmatism, myopia and hyperopia can be treated by software adjustment of the beam scans.
LaserSight Technologies, Inc.
The new LaserScan LSX utilizes LaserSight's patented scanning delivery system integrating new leading edge technology. The LaserScan LSX uses a patented scanning system to deliver a 1-mm low energy "flying spot" in a proprietary alternating, multi-zone, multi-pass strategy. With each pass, about 2 microns of tissue are precisely removed to produce a finely polished corneal surface. Unlike older broad beam technologies, no rings or ridges are produced. Studies now show that smoother ablations may produce less haze, faster healing and more stable clinical results. Integral to each system is flexibility in treatment parameters including gently tapered transition zones.
Manufacture and sales of refractive laser systems, keratome systems, keratome blade products, and aesthetic lasers. LaserSight pioneered refractive laser systems using 193 nm, high resolution, scanning delivery. Both patient fixation and an optional automated tracking system are available. Astigmatism, hyperopia and myopia can be treated with software adjustments of the scanning mechanism. Watch this space for a future " quick-time" or "M-peg" clip of calibration, and actual treatment of myopia, astigmatism and hyperopia.
The LaserHarmonic-1 and LaserHarmonic-2 are solid state lasers still in the development stage. The former is flash lamp pumped and employs the fifth harmonic of a Nd:Yag at 213nm, and the latter is a diode pumped fifth harmonic Nd:YLF laser at 209nm.
Nidek, Inc.
EC-5000 This is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is a rectangular slit which both scans, dynamically rotates, and overlaps. The rotation of the scan is designed to eliminate circular f-stop ridges and increase the smoothness of the ablation. Centration is controlled by the surgeon with a "joy" stick mechanism to follow the patient's eye. Astigmatism and myopia can be treated by software adjustment of the beam scans. At the time of writing we do not have any result data for this machine. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of myopia, and astigmatism.
Novatec LASER SYSTEMS INC
Lightblade (TM) This is an solid state c. 208nm non excimer scanning system based upon the fourth harmonic of a titanium sapphire crystal. The scanning beam is a 200-300um variable size spot. Centration is accomplished by an active tracking mechanism which locks to have the laser follow movement by the patient's eye. Astigmatism and hyperopia can also be treated by software adjustment of the spot scans. At the time of writing we do not have any result data for astigmatism of hyperopia treatment. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
Summit Technology
Excimed, Omnimed, Apogee, Apex These are Argon Fluoride 193 nm excimer wide beam systems. The 1990 version of the Eximed machine had optical zones of only 4.5 and 5.0 mm. The Omnimed and Eximed versions increased the optical zone to 6.0 and 6.5mm. (The Apex machine has an optical zone of 6.5mm blending out to 9.4mm transition zone. The mask for simple myopia is an f-stop like mechanism located internally in the beam path. Summit has chosen to use custom crafted ablatable masks in the rail or beam path for the astigmatism and hyperopic correction. These masks protect the corneal tissue under them until the tapered mask is removed by laser pulses. The area without a mask will receive the full laser ablation. We have no data at the time of writing concerning the effectiveness of the ablatable masks for the astigmatic element of myopia treatment. Laser calibration is done by an internal 2 minute beam profile test. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
VisX
20/15, 20/20, STAR (TM) These are Argon Fluoride 193 nm excimer wide beam systems, the STAR(TM) version being the most recent evolution of the machine. The STAR machine has a standard 6mm optical zone which is expandible to 8mm for future applications. The mask for simple myopia is an f-stop like mechanism located internally in the beam path. The astigmatic module masks and hyperopic module masks are located internally in the beam path. The hyperopic module has an ablation zone of 9mm. Laser calibration is performed automatically at the start of each day, and between cases. A plastic test card read on a standard lensometer verifies the calibration. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
Automated Lamellar Keratectomy (ALK) vs
ALK-E or LASIK or "FLAP and ZAP"
As a preamble to discussion of ALK (and RK) it is nessary to remark that as of January 1996 ALK is a anomaly largely confined to the USA. The reason is simple- the FDA in its "wisdom" has only approved one laser machine for PRK use, and only to -7.00 diopters correction. Mechanical surgical operations on the other hand are "approved" and thus American Ophthalmologists effectively have one hand tied behind their backs. They are allowed to perform ALK and RK but not PRK. The precision and efficacy of refractive laser technology have rendered ALK and RK essentially extinct in the rest of the world.
ALK is a purely mechanical method of changing the refractive power of the cornea. It involves removing a top layer of cornea with an automated instrument and then making a second incision (the refractive incision) in order to remove tissue for myopia or adding tissue (i.e. donor cornea) for hyperopia. The first incision is meant to remove a circular button of cornea c. 8mm in diameter, but to leave one edge hinged so that after the refractive portion of the operation is complete the hinged corneal surface flap can be repositioned. The first incision is easier to perform because the cornea which is only 0.55 mm thick can be flattened and thus held without moving so that a diamond knife can make a slice of uniform thickness from one side leaving the opposite side hinged. In the case of myopia a second incision must be made to remove a curved (lens shaped) piece of tissue from the cornea's middle tissue (stroma). This tissue can be removed from the back surface of the slice or the front surface of the remaining cornea. The first slice, which is usually hinged (i.e. not completely removed) is then replaced on the cornea and held in place with or without a contact lens until the flap can reattach itself to the rest of the cornea - i.e. heal with a change in the shape of the corneal surface equivalent to the change in lens needed to satisfy the refractive needs.
The more difficult technical problem with the mechanical ALK procedure is the (second) refractive incision which must remove an extremely thin slice of corneal tissue complete with tapered edges. There is a jelly-like consistency to the corneal tissue underneath the surface and this leads to significant limits to the precision of the procedure.
An improved method of making the refractive incision is to use the excimer laser. This method is called ALK-E OR LASIK rather than ALK (Automated Lammellar Keratectomy - Excimer laser or Laser in Situ Keratomileusis). The use of the laser to sculpt either a - (myopic) or + (hyperopic) lens in the remaining corneal tissue allows the extreme precision of the refractive laserÍs surgical ability to significantly enhance the technique. Since the first or surface incision with the microkeratome is technically easier than the second or refractive incision it makes good sense to use the extreme optical precision of the refractive laser to achieve the desired correction of the corneal refraction. This technique allows preservation of the corneal basement epithelial layer knows as Bowman's membrane and in the absence of complications from the reattachment and healing of this flap, the refractive results can be rapid and superb.
MEL 60- This is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is rectangular and measures 1mm by 10 mm. The system uses a limbal suction cup mechanism to fix centration and computer controlled rotating masks which fit into the suction cup mechanism. The mask for simple myopia is an f-stop like mechanism. There are different masks used for myopia with astigmatism, hyperopia, and for pure astigmatism. The masks rotate within the suction cup in order to control any axis of extra ablation as needed for astigmatism correction. Laser calibration is done by visual inspection of a 1um thick metal foil which requires 9 laser passes for removal. There is a layer of red under the silver foil making efficacy of removal easily monitored. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
ALCON
LADARVision® System and CustomCornea® - The LADARVision® System consists of the LADARVision® 4000 laser and the LADARWave® Aberrometer. The LADARVision excimer laser is a small-spot scanning laser with a laser radar tracking device. FDA approved for wavefront-guided ablations.
Bausch & Lomb Technolas 217 Excimer Laser with PLANOSCAN
Technolas 217 Workstation - this is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is a circular spot which can be size adjusted. Centration is accomplished by an active "pupil" tracking mechanism which locks on to the pupil image and will have the laser follow any movement by the patient's eye. Active Infra-red Eye Tracker and passive monitor interrupts laser beam on movement in excess of 3 mm range (1.5 mm radius). Astigmatism, myopia and hyperopia can be treated by software adjustment of the beam scans.
LaserSight Technologies, Inc.
The new LaserScan LSX utilizes LaserSight's patented scanning delivery system integrating new leading edge technology. The LaserScan LSX uses a patented scanning system to deliver a 1-mm low energy "flying spot" in a proprietary alternating, multi-zone, multi-pass strategy. With each pass, about 2 microns of tissue are precisely removed to produce a finely polished corneal surface. Unlike older broad beam technologies, no rings or ridges are produced. Studies now show that smoother ablations may produce less haze, faster healing and more stable clinical results. Integral to each system is flexibility in treatment parameters including gently tapered transition zones.
Manufacture and sales of refractive laser systems, keratome systems, keratome blade products, and aesthetic lasers. LaserSight pioneered refractive laser systems using 193 nm, high resolution, scanning delivery. Both patient fixation and an optional automated tracking system are available. Astigmatism, hyperopia and myopia can be treated with software adjustments of the scanning mechanism. Watch this space for a future " quick-time" or "M-peg" clip of calibration, and actual treatment of myopia, astigmatism and hyperopia.
The LaserHarmonic-1 and LaserHarmonic-2 are solid state lasers still in the development stage. The former is flash lamp pumped and employs the fifth harmonic of a Nd:Yag at 213nm, and the latter is a diode pumped fifth harmonic Nd:YLF laser at 209nm.
Nidek, Inc.
EC-5000 This is an Argon Fluoride 193 nm excimer scanning system. The scanning beam is a rectangular slit which both scans, dynamically rotates, and overlaps. The rotation of the scan is designed to eliminate circular f-stop ridges and increase the smoothness of the ablation. Centration is controlled by the surgeon with a "joy" stick mechanism to follow the patient's eye. Astigmatism and myopia can be treated by software adjustment of the beam scans. At the time of writing we do not have any result data for this machine. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of myopia, and astigmatism.
Novatec LASER SYSTEMS INC
Lightblade (TM) This is an solid state c. 208nm non excimer scanning system based upon the fourth harmonic of a titanium sapphire crystal. The scanning beam is a 200-300um variable size spot. Centration is accomplished by an active tracking mechanism which locks to have the laser follow movement by the patient's eye. Astigmatism and hyperopia can also be treated by software adjustment of the spot scans. At the time of writing we do not have any result data for astigmatism of hyperopia treatment. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
Summit Technology
Excimed, Omnimed, Apogee, Apex These are Argon Fluoride 193 nm excimer wide beam systems. The 1990 version of the Eximed machine had optical zones of only 4.5 and 5.0 mm. The Omnimed and Eximed versions increased the optical zone to 6.0 and 6.5mm. (The Apex machine has an optical zone of 6.5mm blending out to 9.4mm transition zone. The mask for simple myopia is an f-stop like mechanism located internally in the beam path. Summit has chosen to use custom crafted ablatable masks in the rail or beam path for the astigmatism and hyperopic correction. These masks protect the corneal tissue under them until the tapered mask is removed by laser pulses. The area without a mask will receive the full laser ablation. We have no data at the time of writing concerning the effectiveness of the ablatable masks for the astigmatic element of myopia treatment. Laser calibration is done by an internal 2 minute beam profile test. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
VisX
20/15, 20/20, STAR (TM) These are Argon Fluoride 193 nm excimer wide beam systems, the STAR(TM) version being the most recent evolution of the machine. The STAR machine has a standard 6mm optical zone which is expandible to 8mm for future applications. The mask for simple myopia is an f-stop like mechanism located internally in the beam path. The astigmatic module masks and hyperopic module masks are located internally in the beam path. The hyperopic module has an ablation zone of 9mm. Laser calibration is performed automatically at the start of each day, and between cases. A plastic test card read on a standard lensometer verifies the calibration. Watch this space for a future "quick-time" or "M-peg" clip of calibration, and actual treatment of hyperopia, myopia, and astigmatism.
Automated Lamellar Keratectomy (ALK) vs
ALK-E or LASIK or "FLAP and ZAP"
As a preamble to discussion of ALK (and RK) it is nessary to remark that as of January 1996 ALK is a anomaly largely confined to the USA. The reason is simple- the FDA in its "wisdom" has only approved one laser machine for PRK use, and only to -7.00 diopters correction. Mechanical surgical operations on the other hand are "approved" and thus American Ophthalmologists effectively have one hand tied behind their backs. They are allowed to perform ALK and RK but not PRK. The precision and efficacy of refractive laser technology have rendered ALK and RK essentially extinct in the rest of the world.
ALK is a purely mechanical method of changing the refractive power of the cornea. It involves removing a top layer of cornea with an automated instrument and then making a second incision (the refractive incision) in order to remove tissue for myopia or adding tissue (i.e. donor cornea) for hyperopia. The first incision is meant to remove a circular button of cornea c. 8mm in diameter, but to leave one edge hinged so that after the refractive portion of the operation is complete the hinged corneal surface flap can be repositioned. The first incision is easier to perform because the cornea which is only 0.55 mm thick can be flattened and thus held without moving so that a diamond knife can make a slice of uniform thickness from one side leaving the opposite side hinged. In the case of myopia a second incision must be made to remove a curved (lens shaped) piece of tissue from the cornea's middle tissue (stroma). This tissue can be removed from the back surface of the slice or the front surface of the remaining cornea. The first slice, which is usually hinged (i.e. not completely removed) is then replaced on the cornea and held in place with or without a contact lens until the flap can reattach itself to the rest of the cornea - i.e. heal with a change in the shape of the corneal surface equivalent to the change in lens needed to satisfy the refractive needs.
The more difficult technical problem with the mechanical ALK procedure is the (second) refractive incision which must remove an extremely thin slice of corneal tissue complete with tapered edges. There is a jelly-like consistency to the corneal tissue underneath the surface and this leads to significant limits to the precision of the procedure.
An improved method of making the refractive incision is to use the excimer laser. This method is called ALK-E OR LASIK rather than ALK (Automated Lammellar Keratectomy - Excimer laser or Laser in Situ Keratomileusis). The use of the laser to sculpt either a - (myopic) or + (hyperopic) lens in the remaining corneal tissue allows the extreme precision of the refractive laserÍs surgical ability to significantly enhance the technique. Since the first or surface incision with the microkeratome is technically easier than the second or refractive incision it makes good sense to use the extreme optical precision of the refractive laser to achieve the desired correction of the corneal refraction. This technique allows preservation of the corneal basement epithelial layer knows as Bowman's membrane and in the absence of complications from the reattachment and healing of this flap, the refractive results can be rapid and superb.
PRK Laser Types
Current PRK lasers are best classified by laser source (either Argon-Fluoride excimer lasers or solid state) and beam type (broad beam or scanning beam). Laser technology and computer control software has evolved significantly since the first normally sighted eyes were treated in 1987. Initial PRK treatments used 3.5 and 4mm optical zones so as to minimize the depth of ablation. Since many pupils dilate to 5mm it is not surprising that edge glare and light sensitivity were common complications. Ablation diameter increase with edge smoothing has been implemented to solve many edge glare problems. Wide or broad beam machines initially had problems caused by the use of nitrogen flow to disperse vaporized tissue and with the occurrence of unvaporized central islands. Stoppage of nitrogen flow and modification of computer generated treatment regimes has largely eliminated these problems.
The US Food & Drug Administration (FDA) has been cautious, rigid, and slow to approve PRK for widespread use within the USA. There has been speculation that the reason for the current caution is embarrassment over a previous premature approved of the surgical procedure of radial keratotomy (RK). Many observers have feared that the apparent bureaucratic rigidity might impede the implementation of future needed changes to equipment or procedures prior to long and inflexible testing schedules. However, recently the FDA surprised its critics when, with the final approval of the Summit Laser, they insisted upon increasing the size of the optical zone from that tested in the preapproval trials. In the US a number of other laser manufacturers are progressing or almost through FDA trials. In contrast, most other jurisdictions including Europe and Canada, have, without the "benefit" of as vigorous an approval process, had the freedom to amend and improve equipment and treatment regimes as improvements presented themselves. There is now worldwide a large and expanding experience with many varied laser machines and evolving technical improvements.
The US Food & Drug Administration (FDA) has been cautious, rigid, and slow to approve PRK for widespread use within the USA. There has been speculation that the reason for the current caution is embarrassment over a previous premature approved of the surgical procedure of radial keratotomy (RK). Many observers have feared that the apparent bureaucratic rigidity might impede the implementation of future needed changes to equipment or procedures prior to long and inflexible testing schedules. However, recently the FDA surprised its critics when, with the final approval of the Summit Laser, they insisted upon increasing the size of the optical zone from that tested in the preapproval trials. In the US a number of other laser manufacturers are progressing or almost through FDA trials. In contrast, most other jurisdictions including Europe and Canada, have, without the "benefit" of as vigorous an approval process, had the freedom to amend and improve equipment and treatment regimes as improvements presented themselves. There is now worldwide a large and expanding experience with many varied laser machines and evolving technical improvements.
PRK Laser Energy
Visible light and all other forms of electromagnetic radiation carry energy. Light passes through windows, radio waves pass through buildings and x-rays pass through people, but each of these energy forms can also interact and thus release the energy. Beneficial or harmful effects will occur depending upon the wavelength of the energy source, the strength of the radiation, and what substance interacts or is struck.
Lasers are a method of producing an intense beam of energy with a precise wavelength. The first optical laser appeared in 1960 (1). The early medical lasers (2) produced visible light wavelengths which relied upon the transfer of heat energy to burn or photo coagulate tissue. Later lasers (3) used infrared (IR) wavelengths whose heat and energy was sufficient to either photo vaporize or photo disrupt (explode) tissue. Ultraviolet (UV) lasers were first suggested in 1975 (4) and subsequently a class of lasers known as Excimer lasers has evolved. The argon fluoride (ArF) version emits radiation of 193.3 nm wavelength. This is the laser which has revolutionized refractive surgery because when this laser interacts with tissue it removes only a fraction of the cell with virtually no damage to surrounding cells. A recent Ophthalmology textbook (5) has excellent comprehensive reviews showing collections of pioneering photomicrographs. We hope soon to receive permission to reproduce extraordinary photographs of grooves in a human hair (6), and laser incisions in human cornea (7). The remarkable feature is incredibly smooth incisions with no evidence of heat damage in immediately adjacent tissue. This could be called a cold laser. It turns out that wavelengths in the 200 nm range deliver just the right energy to break intermolecular bonds and simply ablate tissue without collateral damage to immediately adjacent cells. A longer wavelength such as a 248 nm (KrF Excimer) radiation burns a wide path of adjacent tissue in addition to the directly affected tissue. Since longer UV wavelengths (UV-B) are known to increase the occurrence of skin cancer a number of scientific studies have been done to study the possibility of 193 nm (UV-C) radiation causing cancer and each one has shown that 193 nm radiation does not damage DNA (8). Wavelengths shorter than 100 nm enter the X-Ray bands. X-Rays pass through cell and can also cause Cancer. Excimer 193 nm rays strike a cell surface and ablate only 0.25 (9) um of tissue. Since the distance from cell wall to nucleus in a corneal epithelial cell is 1.5 to 3.0 um (10) it is thought that the nuclei are either shielded from the radiation or destroyed with little potential for mutagenesis (cancer production).
The action of 193 nm excimer radiation is even more elegant than ablating 0.25 um of tissue. It turns out that after each laser pulse the remaining cell elements are resealed by the formation of a pseudo membrane or new layer or membrane. It is helpful to think of corneal cells as rather like grapes with a liquid center and surrounding membrane which holds the liquid center in. You can imagine each laser pulse removing 1/10 of the grape and resealing the portion of the grape (cell) not ablated or destroyed! To place the 0.25 um ablation in perspective, some corneal epithelial cells are 18 um tall and the depth of the cornea at center is 500 um.
Lasers are a method of producing an intense beam of energy with a precise wavelength. The first optical laser appeared in 1960 (1). The early medical lasers (2) produced visible light wavelengths which relied upon the transfer of heat energy to burn or photo coagulate tissue. Later lasers (3) used infrared (IR) wavelengths whose heat and energy was sufficient to either photo vaporize or photo disrupt (explode) tissue. Ultraviolet (UV) lasers were first suggested in 1975 (4) and subsequently a class of lasers known as Excimer lasers has evolved. The argon fluoride (ArF) version emits radiation of 193.3 nm wavelength. This is the laser which has revolutionized refractive surgery because when this laser interacts with tissue it removes only a fraction of the cell with virtually no damage to surrounding cells. A recent Ophthalmology textbook (5) has excellent comprehensive reviews showing collections of pioneering photomicrographs. We hope soon to receive permission to reproduce extraordinary photographs of grooves in a human hair (6), and laser incisions in human cornea (7). The remarkable feature is incredibly smooth incisions with no evidence of heat damage in immediately adjacent tissue. This could be called a cold laser. It turns out that wavelengths in the 200 nm range deliver just the right energy to break intermolecular bonds and simply ablate tissue without collateral damage to immediately adjacent cells. A longer wavelength such as a 248 nm (KrF Excimer) radiation burns a wide path of adjacent tissue in addition to the directly affected tissue. Since longer UV wavelengths (UV-B) are known to increase the occurrence of skin cancer a number of scientific studies have been done to study the possibility of 193 nm (UV-C) radiation causing cancer and each one has shown that 193 nm radiation does not damage DNA (8). Wavelengths shorter than 100 nm enter the X-Ray bands. X-Rays pass through cell and can also cause Cancer. Excimer 193 nm rays strike a cell surface and ablate only 0.25 (9) um of tissue. Since the distance from cell wall to nucleus in a corneal epithelial cell is 1.5 to 3.0 um (10) it is thought that the nuclei are either shielded from the radiation or destroyed with little potential for mutagenesis (cancer production).
The action of 193 nm excimer radiation is even more elegant than ablating 0.25 um of tissue. It turns out that after each laser pulse the remaining cell elements are resealed by the formation of a pseudo membrane or new layer or membrane. It is helpful to think of corneal cells as rather like grapes with a liquid center and surrounding membrane which holds the liquid center in. You can imagine each laser pulse removing 1/10 of the grape and resealing the portion of the grape (cell) not ablated or destroyed! To place the 0.25 um ablation in perspective, some corneal epithelial cells are 18 um tall and the depth of the cornea at center is 500 um.
The Magic of PRK
The magic of Photo Refractive Keratectomy (PRK) is a surgical precision unprecedented in human history. Excimer Laser power coupled with today's computers allows one laser pulse to remove as little as one quarter (0.25 nm) of a micrometer (or micron) of corneal tissue. This is exquisite control! In PRK the focusing power of glasses or contact lenses is sculpted directly unto the cornea or front window of the eye. The new and special laser actually cleaves individual molecular bonds to remove tissue with no damage to surrounding tissue. Computer programs control the surface sculpting to ensure the highest possible accuracy and success of the intended refractive change.
LASIK - eye surgery
Laser eye surgery was first performed to correct near-sightedness in Germany in 1988. Since then it has quickly spread throughout the world and is available in most developed countries. It has been particularly popular in Europe, Asia, and North America, especially the USA and Canada. In the USA, the FDA first approved an excimer laser to be used for laser eye surgery in 1995. The excimer laser was approved for use in LASIK in the USA in 1998.
LASIK is perhaps the most popular elective surgery available today. It is estimated that over 1,000,000 LASIK procedures are performed annually in the USA.
Availability
LASIK surgeons and clinics are available in all major cities including New York City, Los Angeles, Miami, San Francisco, Las Vegas, San Antonio, San Jose, Milwaukee, Boston, and San Diego.
There are also LASIK clinics and surgeons available in every state in the United States including
New York, California, Colorado, and New Jersey.
There are more than 5,000 LASIK surgeons who are performing LASIK eye surgery.
General Information
With increased interest in LASIK, there have been an increased number of LASIK providers as well. While LASIK eye surgery is considered to be a very safe and effective treatment in general, patients would be advised to select a LASIK surgeon with caution. Despite the increased advantage of advanced technology, the LASIK surgeon is still considered to be a vital and important part of the treatment and the selection process is vital in improving the chances of a good result.
In addition to selecting the correct LASIK surgeon, it is helpful to know the technology that is available today. LASIK technology has changed rapidly over the years and LASIK providers who have not kept up with the advancements could possibly be harming their patients. Good results with your surgery depend upon a variety of factors, including experience, skill, technology, wise decision-making, good patient selection, and good people skills. Each of the factors can affect the results of your surgery.
LASIK eye surgery has brought happiness and freedom from glasses and contact lenses to millions of people. The vast majority of LASIK patients is very satisfied with the results and would recommend their friends to have the procedure. A very small minority experience side effects or complications which leads them to regret their decision to undergo LASIK surgery. These side effects can range from mild temporary irritation to long term visual problems and possibly even loss of vision.
Please consider all the information provided before contacting your local LASIK providers. It is often wise to contact several LASIK surgeons so that you can determine which surgeon is providing the best possible service and will offer the best chance at having good LASIK results. While it is often difficult for someone outside of the business to weigh the factors in making a good decision, this web site will offer a variety of information to offer you a better opportunity for good LASIK results.
More Specific Information
LASIK articles are written periodically with respect to more specific information including information regarding clinics and surgeons in various markets, new technology, what to watch out for, and other information related to LASIK. As a service we also post articles dealing with other eye-related issues not specifically dealing with LASIK but often of interest to our readers.
LASIK is perhaps the most popular elective surgery available today. It is estimated that over 1,000,000 LASIK procedures are performed annually in the USA.
Availability
LASIK surgeons and clinics are available in all major cities including New York City, Los Angeles, Miami, San Francisco, Las Vegas, San Antonio, San Jose, Milwaukee, Boston, and San Diego.
There are also LASIK clinics and surgeons available in every state in the United States including
New York, California, Colorado, and New Jersey.
There are more than 5,000 LASIK surgeons who are performing LASIK eye surgery.
General Information
With increased interest in LASIK, there have been an increased number of LASIK providers as well. While LASIK eye surgery is considered to be a very safe and effective treatment in general, patients would be advised to select a LASIK surgeon with caution. Despite the increased advantage of advanced technology, the LASIK surgeon is still considered to be a vital and important part of the treatment and the selection process is vital in improving the chances of a good result.
In addition to selecting the correct LASIK surgeon, it is helpful to know the technology that is available today. LASIK technology has changed rapidly over the years and LASIK providers who have not kept up with the advancements could possibly be harming their patients. Good results with your surgery depend upon a variety of factors, including experience, skill, technology, wise decision-making, good patient selection, and good people skills. Each of the factors can affect the results of your surgery.
LASIK eye surgery has brought happiness and freedom from glasses and contact lenses to millions of people. The vast majority of LASIK patients is very satisfied with the results and would recommend their friends to have the procedure. A very small minority experience side effects or complications which leads them to regret their decision to undergo LASIK surgery. These side effects can range from mild temporary irritation to long term visual problems and possibly even loss of vision.
Please consider all the information provided before contacting your local LASIK providers. It is often wise to contact several LASIK surgeons so that you can determine which surgeon is providing the best possible service and will offer the best chance at having good LASIK results. While it is often difficult for someone outside of the business to weigh the factors in making a good decision, this web site will offer a variety of information to offer you a better opportunity for good LASIK results.
More Specific Information
LASIK articles are written periodically with respect to more specific information including information regarding clinics and surgeons in various markets, new technology, what to watch out for, and other information related to LASIK. As a service we also post articles dealing with other eye-related issues not specifically dealing with LASIK but often of interest to our readers.
Laser eye surgery risks highlighted
Consumer experts have warned that patients undergoing laser eye surgery are not being told about the risks they could be taking with their sight.
Laser surgery, which can cost thousands of pounds, is increasingly popular.
But the investigation by Health Which? also reveals any doctor can carry out the treatment after just a few days of training - they do not need a specialist qualification.
The magazine also found complication rates vary between surgeons and clinics.
Around 100,000 people, tired of wearing glasses or contact lenses, undergo corrective laser eye surgery in the UK every year.
The procedure is seen as quick and simple, and has received many celebrity endorsements.
Health Which? looked at clinics offering the Lasik procedure - the most popular on offer.
But whilst some highlight a low risk of complications with the procedure, others say the risk is non-existent.
'Misleading adverts'
In very rare cases, complications can lead to corneal ectasia, where fluid pressure builds up on the eye.
Patients can need a corneal transplant to correct the condition.
Other complications, though deemed "minor" by clinics, occur "relatively frequently", according to a review by the American Academy of Ophthalmology.
Patients can experience dry eyes or night vision problems, which can affect ability to drive or work in the evening or in dim light.
Health Which? also says that the Medical Defence Union and the Medical Protection Society, both doctors' insurance companies, are raising the fees they charge doctors working in this field because of increased compensation claims by patients.
Questions
David Gartry, a consultant ophthalmologist at Moorfields Eye Hospital has helped draw up Royal College of Ophthalmologist' guidelines on who should carry out laser eye surgery.
The guidelines say that only doctors with specialist training should carry out the procedure.
Mr Gartry told BBC News Online patients should find out as much as possible about the surgeon likely to carry out their operation.
"This is a situation where patients are responding to adverts, or even incentives.
"Patients should be asking the sort of questions they would ask if they were having, say, a hernia operation.
"What are the complication rates? What will happen if something goes wrong? Will I see the surgeon again?"
Dan Reinstein, who is developing safety guidelines for the Medical Protection Society, added: "Expert surgeons are better equipped to avoid complications even if they have not previously seen them.
"And when these do occur, trained experts will have the knowledge and ability to correct them."
'Highest clinical standards'
Sue Freeman, managing editor of Health Which?, said: "Patients shouldn't be taken in by claims about the safety and success rates of laser eye surgery and in particular about so called 'minor complications'.
"While some people will be able to throw away their glasses, this won't be the case for everyone."
She added: "Patients should be fully informed of the possible risks and of the complication rates of clinics and individual surgeons.
"Until patients are able to make informed choice, they need to do a lot of research and ask a lot of hard questions of surgeons and clinics."
Here are a selection of your comments on this subject.
If my wife had known what it was going to be like she would never have had it done
G Fuller, UK
My wife had corrective laser treatment in November 2002 and all the literature she received quoted 'best case' examples of people being back at work the next day. Unfortunately she experienced massive discomfort and complete blindness for a week which failed to be controlled by the painkillers and sleeping pills prescribed by the clinic. In her own words "if she had known what it was going to be like she would never have had it done".
G Fuller, UK
Following surgery at the age of 44, I now have 20-20 vision, can use normal sunglasses (essential in Australia and at high altitude) and no longer have problems with rain or fogging. I saw a specialist surgeon in Belgium who used the latest equipment. I have had one (free) adjustment operation to correct some astigmatism in one eye.
I have experienced some minor double-vision, slight loss of night vision, and initially starbursts/haloes around strong light sources - the latter now much reduced. For me these are very minor compared with the joy of being able to see the stars with the naked eye for the first time. I was given a video recording of the operation but this is not for the squeamish, and best seen afterwards.
Charles Barran, Australia
After many years of consideration I finally took the decision to have laser treatment in December 2001. I opted for Lasek and was talked through all the possible complications and even had to take a little test to ensure I was fully aware of all possible side effects. After a thorough consultation I then had both eyes done simultaneously. I won't pretend the days following the treatment were bliss, I was in some discomfort for 3 to 4 days but after that had passed my eyes soon began to heal.
It was strange but having worn glasses for so long for a month or so afterwards I was still trying to push glasses that weren't there back up the bridge of my nose! It is now over a year since and I have perfect 20/20 vision. Just very occasionally my eyes are a little dry in the morning but I consider this a tiny inconvenience.
Edward Lacey, UK
I'd like to know if Sue Freeman would recommend micro lenses inserted into the eye as a better option than Lasik eye surgery. Would she be so kind as to find out on my behalf. I would like to lose my glasses. I did intend to have Lasik surgery but have now been scared off with the latest news regarding unsuccessful operations.
Vincent Jones, Dorset, UK
I had Lasik surgery last year and it was the best thing I ever did. I was fully informed by the company regarding any potential risks (and clear details on the procedures are on their website anyway). It was great just waking up the next day and not having to fumble around looking for glasses, and no fussing about shoving bits of plastic in my eyes each day!
Dave, UK
I had laser surgery in June 2001 and have been more than satisfied with the results and the service I received. I felt under no pressure to make a decision and that I was able to make an informed choice to go ahead with the procedure. I agree though that you do need to ask questions and be aware that there are risks - but isn't this the case for any sort of medical procedure? It is also essential to use a reputable company, unfortunately there are rouges out there, look at cosmetic surgery.
Kate Austin, England
Laser surgery, which can cost thousands of pounds, is increasingly popular.
But the investigation by Health Which? also reveals any doctor can carry out the treatment after just a few days of training - they do not need a specialist qualification.
The magazine also found complication rates vary between surgeons and clinics.
Around 100,000 people, tired of wearing glasses or contact lenses, undergo corrective laser eye surgery in the UK every year.
The procedure is seen as quick and simple, and has received many celebrity endorsements.
Health Which? looked at clinics offering the Lasik procedure - the most popular on offer.
But whilst some highlight a low risk of complications with the procedure, others say the risk is non-existent.
'Misleading adverts'
In very rare cases, complications can lead to corneal ectasia, where fluid pressure builds up on the eye.
Patients can need a corneal transplant to correct the condition.
Other complications, though deemed "minor" by clinics, occur "relatively frequently", according to a review by the American Academy of Ophthalmology.
Patients can experience dry eyes or night vision problems, which can affect ability to drive or work in the evening or in dim light.
Health Which? also says that the Medical Defence Union and the Medical Protection Society, both doctors' insurance companies, are raising the fees they charge doctors working in this field because of increased compensation claims by patients.
Questions
David Gartry, a consultant ophthalmologist at Moorfields Eye Hospital has helped draw up Royal College of Ophthalmologist' guidelines on who should carry out laser eye surgery.
The guidelines say that only doctors with specialist training should carry out the procedure.
Mr Gartry told BBC News Online patients should find out as much as possible about the surgeon likely to carry out their operation.
"This is a situation where patients are responding to adverts, or even incentives.
"Patients should be asking the sort of questions they would ask if they were having, say, a hernia operation.
"What are the complication rates? What will happen if something goes wrong? Will I see the surgeon again?"
Dan Reinstein, who is developing safety guidelines for the Medical Protection Society, added: "Expert surgeons are better equipped to avoid complications even if they have not previously seen them.
"And when these do occur, trained experts will have the knowledge and ability to correct them."
'Highest clinical standards'
Sue Freeman, managing editor of Health Which?, said: "Patients shouldn't be taken in by claims about the safety and success rates of laser eye surgery and in particular about so called 'minor complications'.
"While some people will be able to throw away their glasses, this won't be the case for everyone."
She added: "Patients should be fully informed of the possible risks and of the complication rates of clinics and individual surgeons.
"Until patients are able to make informed choice, they need to do a lot of research and ask a lot of hard questions of surgeons and clinics."
Here are a selection of your comments on this subject.
If my wife had known what it was going to be like she would never have had it done
G Fuller, UK
My wife had corrective laser treatment in November 2002 and all the literature she received quoted 'best case' examples of people being back at work the next day. Unfortunately she experienced massive discomfort and complete blindness for a week which failed to be controlled by the painkillers and sleeping pills prescribed by the clinic. In her own words "if she had known what it was going to be like she would never have had it done".
G Fuller, UK
Following surgery at the age of 44, I now have 20-20 vision, can use normal sunglasses (essential in Australia and at high altitude) and no longer have problems with rain or fogging. I saw a specialist surgeon in Belgium who used the latest equipment. I have had one (free) adjustment operation to correct some astigmatism in one eye.
I have experienced some minor double-vision, slight loss of night vision, and initially starbursts/haloes around strong light sources - the latter now much reduced. For me these are very minor compared with the joy of being able to see the stars with the naked eye for the first time. I was given a video recording of the operation but this is not for the squeamish, and best seen afterwards.
Charles Barran, Australia
After many years of consideration I finally took the decision to have laser treatment in December 2001. I opted for Lasek and was talked through all the possible complications and even had to take a little test to ensure I was fully aware of all possible side effects. After a thorough consultation I then had both eyes done simultaneously. I won't pretend the days following the treatment were bliss, I was in some discomfort for 3 to 4 days but after that had passed my eyes soon began to heal.
It was strange but having worn glasses for so long for a month or so afterwards I was still trying to push glasses that weren't there back up the bridge of my nose! It is now over a year since and I have perfect 20/20 vision. Just very occasionally my eyes are a little dry in the morning but I consider this a tiny inconvenience.
Edward Lacey, UK
I'd like to know if Sue Freeman would recommend micro lenses inserted into the eye as a better option than Lasik eye surgery. Would she be so kind as to find out on my behalf. I would like to lose my glasses. I did intend to have Lasik surgery but have now been scared off with the latest news regarding unsuccessful operations.
Vincent Jones, Dorset, UK
I had Lasik surgery last year and it was the best thing I ever did. I was fully informed by the company regarding any potential risks (and clear details on the procedures are on their website anyway). It was great just waking up the next day and not having to fumble around looking for glasses, and no fussing about shoving bits of plastic in my eyes each day!
Dave, UK
I had laser surgery in June 2001 and have been more than satisfied with the results and the service I received. I felt under no pressure to make a decision and that I was able to make an informed choice to go ahead with the procedure. I agree though that you do need to ask questions and be aware that there are risks - but isn't this the case for any sort of medical procedure? It is also essential to use a reputable company, unfortunately there are rouges out there, look at cosmetic surgery.
Kate Austin, England
Friday, June 26, 2009
LASIK Eye Surgery
| On May 7, I visited my local TLC Laser Eye Center for eye surgery. I began looking into eye surgery way back in December.. At that time, I wore my glasses for a week, then waltzed into my local TLC and tried to get it done the next day. I quickly found out that 1) it wasn't possible for 2 weeks and 2) I couldn't ski for a couple weeks afterward.. Since we were in the midst of a great ski season, I decided to schedule it for May. I failed the LASIK-eligibility and learned I'd have to have PRK instead. The scars on my right eyeball caused me to fail. I received these scars as a boy when a friend and I blew up a .45-70 bullet with a nail and sledgehammer. I was the one holding the nail and couldn't see for the next 3 days. In a nutshell: with LASIK they cut a flap, lift it up and shoot the laser under it. It heals quickly and is relatively painless. PRK has been around since before LASIK. With PRK, they seem to shave your eyeball and then shoot a laser into it. PRK takes a lot longer to heal, but the results are often as good or better than LASIK. Wikipedia has a more technical PRK vs. LASIK reference. The Procedure My mom flew into town for my surgery and drove me to TLC's office on that Thursday morning. It took 2 hours to prep for surgery, with most of the time spent sitting around and talking to my mom. Finally, they asked her to sit in the lobby and took me back to a waiting area. When I walked in the room, there were 2 other patients with surgery gear (funny hat and booties) and masks. They were leaning back, looking at the ceiling with their masks on and eyes closed. I quickly became the 3rd person who looked like this. Right before they started putting drops in my eyes, I remember being terrified that I might never see daylight again. At the very least, I thought I wouldn't see anything but black for the next 3 days. Right before they called me in, the previous patient walked out and muttered "Damn, that burns." Believe me, this is not what you want to hear right before it's your turn. I was led into the operating room, sat down and received numbing drops in my eyes. Less than a minute later, I was led over to the operating table. The rest of the procedure lasted less than 5 minutes. They taped my left eye shut and told me to stare at the red light with my right eye. At this point, they used some contraption to shave my eyeball. It was slightly painful, similar to the mild pain you feel when getting a cavity drilled with Novocaine. After each stroke, the world would ripple like a pebble thrown into in a lake. After 10 strokes or so, they shot a laser into my eye for around 20 seconds. You don't actually see the laser (the red light looks the same), but you can smell your eyeball burning. Each eye only took a few minutes. My mom was able to watch the entire surgery on a television on the other side of a glass wall. The Recovery I was surprised to discover I was immediately able to open my eyes and see normally. Of course, my eyes felt heavy, so I didn't open them wide nor feel like I could. I was led back to the waiting room where I was given a Valium and sent home. I put my sunglasses on when we left and kept my eyes closed for the 5-minute drive home. After arriving at my house, I immediately downed some Tylenol PM and went to bed. It was hard to fall asleep and my eyes began tearing up. There was a dull pain in my eyes that kept the tears flowing for most of the afternoon. It took me 2 hours to fall asleep and I remember my eyes causing my nose to get stuffed up from all the tears. When I woke up that evening, everything was blurry, but I was able to open my eyes and see better than I had previously w/o glasses. I didn't expect anything in the form of good vision and was mostly pre-occupied with trying to stop the pain (which wasn't terrible, but definitely present). I was prescribed Vicodin and started taking it on a regular basis. I was completely unable to watch TV at all that night. Viewing the computer screen was unthinkable. The next morning, my vision was a lot better as evidenced by the tweet from my iPhone. Shortly after, my mom drove me to my eye doctor's office for a 1-day checkup. The results were surprising. Friday night was one of the most painful. Saturday wasn't very painful, but my eyesight was very blurry. That afternoon, it was hard to keep my eyes open. Every time I tried to open them, I felt like I had to sneeze. Fortunately, I was able to watch the Nuggets game. I couldn't see players' numbers, but I was able to see Melo's last-second 3-pointer to win. On Monday, I was able to drive to TLC for my 3-day checkup. Things were definitely blurry, but I didn't feel like it was dangerous for me to be behind the wheel. I was able to work on Monday, but I also had to increase my font sizes to 36pt and used a 30" monitor all day. OS X's Universal Access -> Zoom feature came in awful handy. That night, TV was a LOT clearer than the previous night, but it was still fuzzy. What's it like now? It's been almost 4 weeks and I'm very glad that I had the surgery done. I haven't felt any pain since the Sunday after surgery and I haven't had any issues with dryness. My vision does fluctuate from day-to-day. Some days I feel like I have super-hero vision and other days there's a halo around objects beyond 10 feet. According to my doctor, fluctuations are expected to continue for 6 months. I don't mind since it never gets bad enough to seem strange.. Now I enjoy not having to worry about glasses or contacts when traveling. I love waking up every morning and not having to do anything to improve my vision. I feel like I have more freedom in my life. Getting eye surgery is definitely one of the best things I've ever done. |
Wednesday, March 25, 2009
Vancouver Laser Eye Surgery Centers
Vancouver laser eye surgery centers and clinics receive patrons from around the United States and Canada. People visiting Vancouver on vacation find it convenient to drop by one of its many laser surgery centers for a few minutes of LASIK surgery. Below are some of them.
Coal Harbour LASIK Eye Centres
Dr. Steven Kirzner, is this Vancouver laser eye surgery center's medical director. He has performed over 35,000 successful laser eye procedures since 1991.
Coal Harbour LASIK Eye Centres patients benefit from advances in 3D eye tracking so that they do not have to align their own eye to the laser, as in other procedures that predate 3D eye tracking and iris recognition technology. This technology ensures greater accuracy, alignment, and safety.
Moreover, the technology makes allowances for dilated pupils, eliminating one of the debilitating side effects of conventional laser treatment: poor night vision.
Coal Harbour LASIK Eye Centres uses Bausch & Lomb Zyoptix 100 technology for its procedures.
LASIK MD
Doctors who, together, have performed over 300,000 LASIK surgeries across Canada staff this Vancouver laser eye surgery center.
LASIK MD has pioneered in several areas, such as being the first clinic to use excimer laser in Ontario, Canada and the second in Canada in 1990. LASIK MD surgeons were also the first to use the Total Cornea technique in 1997, which eliminates visual disturbances at night.
The center uses Zero Compression Keratome (to create the corneal flap, saving corneal tissue), ZyoptixTM, and Custom Wavefront LASIK.
LASIK MD uses the Bausch & Lomb 217z laser.
London Place Eye Centre
This Vancouver laser eye surgery clinic has developed a technique called No Touch, a highly safe method of reshaping the cornea in myopic, hyperopic, and astigmatic patients. No Touch uses only laser light (not the usual microkeratome's metal blade) and does not involve manual incision to create a corneal flap.
London Place Eye Centre surgeons are not only internationally recognized in the field of refractive surgery, but also take part in clinical trials to arrive at new techniques. With over 20 years of eye care experience, this Vancouver laser eye surgery center has had over 75,000 triumphant laser eye surgery operations.
London Place Eye Centre uses the VISX STAR S4-IR excimer laser for its No Touch method.
VisionMed
VisionMed's surgeons continuously participate in training and certification programs. They are leaders in refractive surgery research and development, and regularly lecture and teach at international conferences.
This Vancouver laser eye surgery center offers patients Wavefront Scan if they are vulnerable to night vision problems or have large pupils. VisionMed recommends PlanoScan LASIK for a virtually painless and quick procedure, and PlanoScanTM PRK for some patients with specific needs.
VisionMed also offers CustomScan for patients with severe to extreme prescriptions, as well as those with asymmetrical corneas that require a laser system beyond wavefront technology.
Coal Harbour LASIK Eye Centres
Dr. Steven Kirzner, is this Vancouver laser eye surgery center's medical director. He has performed over 35,000 successful laser eye procedures since 1991.
Coal Harbour LASIK Eye Centres patients benefit from advances in 3D eye tracking so that they do not have to align their own eye to the laser, as in other procedures that predate 3D eye tracking and iris recognition technology. This technology ensures greater accuracy, alignment, and safety.
Moreover, the technology makes allowances for dilated pupils, eliminating one of the debilitating side effects of conventional laser treatment: poor night vision.
Coal Harbour LASIK Eye Centres uses Bausch & Lomb Zyoptix 100 technology for its procedures.
LASIK MD
Doctors who, together, have performed over 300,000 LASIK surgeries across Canada staff this Vancouver laser eye surgery center.
LASIK MD has pioneered in several areas, such as being the first clinic to use excimer laser in Ontario, Canada and the second in Canada in 1990. LASIK MD surgeons were also the first to use the Total Cornea technique in 1997, which eliminates visual disturbances at night.
The center uses Zero Compression Keratome (to create the corneal flap, saving corneal tissue), ZyoptixTM, and Custom Wavefront LASIK.
LASIK MD uses the Bausch & Lomb 217z laser.
London Place Eye Centre
This Vancouver laser eye surgery clinic has developed a technique called No Touch, a highly safe method of reshaping the cornea in myopic, hyperopic, and astigmatic patients. No Touch uses only laser light (not the usual microkeratome's metal blade) and does not involve manual incision to create a corneal flap.
London Place Eye Centre surgeons are not only internationally recognized in the field of refractive surgery, but also take part in clinical trials to arrive at new techniques. With over 20 years of eye care experience, this Vancouver laser eye surgery center has had over 75,000 triumphant laser eye surgery operations.
London Place Eye Centre uses the VISX STAR S4-IR excimer laser for its No Touch method.
VisionMed
VisionMed's surgeons continuously participate in training and certification programs. They are leaders in refractive surgery research and development, and regularly lecture and teach at international conferences.
This Vancouver laser eye surgery center offers patients Wavefront Scan if they are vulnerable to night vision problems or have large pupils. VisionMed recommends PlanoScan LASIK for a virtually painless and quick procedure, and PlanoScanTM PRK for some patients with specific needs.
VisionMed also offers CustomScan for patients with severe to extreme prescriptions, as well as those with asymmetrical corneas that require a laser system beyond wavefront technology.
The Benefits of PRK Eye Surgery
(Photorefractive Keratectomy) precedes LASIK surgery. However, many centers still offer the procedure as an alternative to LASIK mainly due to the fact that PRK eye surgery does not invade the cornea by making an incision into the outer layer, as in LASIK.
However, just as there are LASIK eligibility exams, there are also prerequisite eye exams in PRK. Doctors will inquire into the medical history of a patient to discover any allergies or possibilities for complication. Lifestyle and expectations will also be discussed at this stage.
Also, a stable prescription is also required for at least one year.
PRK eye surgery requires that a patient undergo the following:
Corneal thickness
Corneal topography
Dilation exam
Refractive error measurement
Pupil measurements
Tear function analysis
A doctor will require that contact lenses not be used a certain period prior to the PRK eye surgery exam to ensure that refractive measurements are taken correctly. Generally, the requirements for non-use are:
Soft contact lenses = 1 week prior to the eye exam
Hard contact lenses = 2 to 3 weeks prior to the eye exam
PRK involves a longer recovery period compared to LASIK. It also involves a greater degree of discomfort.
Some surgeons and patients agree on PRK due to there being less of a risk that the inner eye pressure will push out against the thinner corneal wall (as in LASIK), causing it to bulge and contributing to ectasia or deteriorating vision over time.
Patients wary about the prospect of a metal blade creating an incision on their eye, which is the riskiest procedure in LASIK surgery, consider PRK as a better alternative.
LASEK
There are two laser eye surgery variations under PRK, one of them is LASEK (Laser Assisted Sub-Epithelial Keratomileusis).
Rather than the epithelial scraping involved in standard PRK, LASEK uses alcohol to soften the epithelium, the surface of the cornea, and remove it.
LASEK's advantage over regular PRK is the faster healing time that more closely approximates recovery from LASIK – although LASEK still avoids using a microkeratome blade to create a corneal flap (as in LASIK).
Epi-LASEK
This second type of modification on PRK uses a separator to lift the epithelium, while the laser reshapes the cornea.
Epi-LASEK reduces discomfort even more and speeds up recovery even faster than LASEK. This procedure is preferred by many who opt for PRK because, more than any other procedure, it approximates the convenience of LASIK surgery the most.
Discomfort and slight pain after PRK eye surgery is sometimes relieved by medication. However, post-op symptoms of blurry or hazy vision are normally allowed disappear naturally with no other treatment apart from regular eye drops prescribed by the doctor.
Patients who have previously undergone LASIK are sometimes advised to undergo PRK for further treatment, since PRK is less invasive.
However, just as there are LASIK eligibility exams, there are also prerequisite eye exams in PRK. Doctors will inquire into the medical history of a patient to discover any allergies or possibilities for complication. Lifestyle and expectations will also be discussed at this stage.
Also, a stable prescription is also required for at least one year.
PRK eye surgery requires that a patient undergo the following:
Corneal thickness
Corneal topography
Dilation exam
Refractive error measurement
Pupil measurements
Tear function analysis
A doctor will require that contact lenses not be used a certain period prior to the PRK eye surgery exam to ensure that refractive measurements are taken correctly. Generally, the requirements for non-use are:
Soft contact lenses = 1 week prior to the eye exam
Hard contact lenses = 2 to 3 weeks prior to the eye exam
PRK involves a longer recovery period compared to LASIK. It also involves a greater degree of discomfort.
Some surgeons and patients agree on PRK due to there being less of a risk that the inner eye pressure will push out against the thinner corneal wall (as in LASIK), causing it to bulge and contributing to ectasia or deteriorating vision over time.
Patients wary about the prospect of a metal blade creating an incision on their eye, which is the riskiest procedure in LASIK surgery, consider PRK as a better alternative.
LASEK
There are two laser eye surgery variations under PRK, one of them is LASEK (Laser Assisted Sub-Epithelial Keratomileusis).
Rather than the epithelial scraping involved in standard PRK, LASEK uses alcohol to soften the epithelium, the surface of the cornea, and remove it.
LASEK's advantage over regular PRK is the faster healing time that more closely approximates recovery from LASIK – although LASEK still avoids using a microkeratome blade to create a corneal flap (as in LASIK).
Epi-LASEK
This second type of modification on PRK uses a separator to lift the epithelium, while the laser reshapes the cornea.
Epi-LASEK reduces discomfort even more and speeds up recovery even faster than LASEK. This procedure is preferred by many who opt for PRK because, more than any other procedure, it approximates the convenience of LASIK surgery the most.
Discomfort and slight pain after PRK eye surgery is sometimes relieved by medication. However, post-op symptoms of blurry or hazy vision are normally allowed disappear naturally with no other treatment apart from regular eye drops prescribed by the doctor.
Patients who have previously undergone LASIK are sometimes advised to undergo PRK for further treatment, since PRK is less invasive.
Prevent Bad Lasik Eye Surgery
Many people with vision problems pin their hopes on Lasik eye surgery to solve their vision dilemmas. Unfortunately, many people get so excited over the anticipated positive results that they fail to seriously consider that a bad Lasik eye surgery outcome IS a serious possibility.
Any medical procedure should be considered with both the positive and negative outcomes. If you are aware of this from the start, then you can prepare better and make well-informed decisions.
Lasik Eye Surgery - A Look at Negative Results
So what can go wrong?
You can suffer from permanent vision loss. This can be caused by an inexperienced doctor who commits a mistake during surgery. This may also be the result of the use of faulty equipment.
You run the risk of actually still needing eyeglasses or contact lenses after surgery.
You may develop chronic dry eyes.
The shape of your cornea may change as a result of the surgery. This will most likely require you to purchase custom-made eyewear, which will be more expensive.
You may develop other vision problems you never had before the operation such as halos, glare, and others.
Bad Lasik Eye Surgery - Contributing Factors
Several factors can contribute to a bad Lasik eye surgery experience.
One: Not realizing that you are a bad candidate for Lasik eye surgery. Do you have dry eyes to begin with? Are you talking any steroids that may hinder proper recovery from the eye surgery? Your condition prior the procedure should be scrutinized and if you are more adamant about having the operation rather than your qualifications for it, then you are setting yourself up for a bad experience.
Two: Your doctor may be inexperienced. You really need to do your homework when it comes to selecting the right doctor to perform Lasik eye surgery. Don't just rely on what your doctor says. Check out his/her medical records and verify if he/she is a member of any reputable medical association. Ask for referrals and call previous clients and ask about their experience. Visit the hospital or place where the doctor will carry out the eye surgery too and see if you are comfortable with the surroundings. Talk several times to your doctor and see how you feel about him/her. In short, are you confident about his/her capabilities?
Three: Last but not the least, be aware of what you should do after Lasik eye surgery. For instance, did you know what you should not, under any circumstances, rub your eyes? Did you know that you should not swim or get into a hot tub for about two to three weeks after surgery?
Talk to your doctor and ask for a list of do's and don’ts. Be sure too to ask about best and worst case scenarios so that you are always prepared in any event.
Any medical procedure should be considered with both the positive and negative outcomes. If you are aware of this from the start, then you can prepare better and make well-informed decisions.
Lasik Eye Surgery - A Look at Negative Results
So what can go wrong?
You can suffer from permanent vision loss. This can be caused by an inexperienced doctor who commits a mistake during surgery. This may also be the result of the use of faulty equipment.
You run the risk of actually still needing eyeglasses or contact lenses after surgery.
You may develop chronic dry eyes.
The shape of your cornea may change as a result of the surgery. This will most likely require you to purchase custom-made eyewear, which will be more expensive.
You may develop other vision problems you never had before the operation such as halos, glare, and others.
Bad Lasik Eye Surgery - Contributing Factors
Several factors can contribute to a bad Lasik eye surgery experience.
One: Not realizing that you are a bad candidate for Lasik eye surgery. Do you have dry eyes to begin with? Are you talking any steroids that may hinder proper recovery from the eye surgery? Your condition prior the procedure should be scrutinized and if you are more adamant about having the operation rather than your qualifications for it, then you are setting yourself up for a bad experience.
Two: Your doctor may be inexperienced. You really need to do your homework when it comes to selecting the right doctor to perform Lasik eye surgery. Don't just rely on what your doctor says. Check out his/her medical records and verify if he/she is a member of any reputable medical association. Ask for referrals and call previous clients and ask about their experience. Visit the hospital or place where the doctor will carry out the eye surgery too and see if you are comfortable with the surroundings. Talk several times to your doctor and see how you feel about him/her. In short, are you confident about his/her capabilities?
Three: Last but not the least, be aware of what you should do after Lasik eye surgery. For instance, did you know what you should not, under any circumstances, rub your eyes? Did you know that you should not swim or get into a hot tub for about two to three weeks after surgery?
Talk to your doctor and ask for a list of do's and don’ts. Be sure too to ask about best and worst case scenarios so that you are always prepared in any event.
What to Expect from Plastic Eye Surgery
Plastic eye surgery — as well as other types of cosmetic plastic surgery — corrects flaws that affect the way you feel about yourself. The enhanced looks that plastic eye surgery offers are aimed at adding to your self-confidence.
During surgery, small incisions are made around the eye with the goal of removing extra fat and muscle to create a firmer, younger-looking eye area. Using the skin's natural folds for the incisions minimizes scarring. Only fine stitches are used for plastic eye surgery.
When plastic eye surgery involves the lower eyelid, incisions are made along the line of the eyelashes and smile creases.
An unnaturally puffy eyelid can be corrected through transconjunctival blepharoplasty, by which excess fat is trimmed. In this procedure, the incision is made inside the lower eyelid. The stitches used in transconjunctival blepharoplasty cannot be seen by the naked eye and dissolve by themselves leaving no scar. This procedure can take anywhere from 1 to 2 hours.
Limits of Plastic Eye Surgery
This type of surgery does not remove fine lines and crow's feet. A separate, skin surface treatment that can enhance your skin's elasticity is an added option.
Unless plastic eye surgery involves a brow lift, it will not help the appearance of a sagging brow. Nor will it eliminate dark circles from under your eyes (for which topical applications exist in the market).
Your plastic surgeon will probably suggest added procedures to enhance your overall look.
Safety Issues
Serious complications from plastic eye surgery are rare. However, the occasional infection or allergic reaction to anesthetics has been known to happen. But the chances of this taking place are drastically minimized by pre-op examination of the patient's medical history, current medication, and preexisting allergies.
Some patients have been known to experience difficulty in closing their eyes, which condition is however generally not permanent.
Bruising, swelling, and redness are typical side effects of any type of plastic surgery, but none of these are permanent and will usually disappear within 10 days.
Plastic eye surgery is more risky for people certain conditions, such as:
Diabetes
Glaucoma and other eye diseases
Heart disease
High blood pressure
Hypothyroidism
Prices
For plastic eye surgery involving the upper eyelid, surgeons may charge in the area of $1,800 to $2,000. For procedures involving the upper and lower eyelids, prices may go as high as $4,500, or more depending on additional costs of anesthetics, medicine, facilities, staff, etc.
Health insurance does not usually cover any kind of cosmetic surgery. However, if plastic eye surgery is done to improve vision (as in the case where the area over the eye droops down to obstruct vision), then your expenses may be reimbursed in whole or in part.
During surgery, small incisions are made around the eye with the goal of removing extra fat and muscle to create a firmer, younger-looking eye area. Using the skin's natural folds for the incisions minimizes scarring. Only fine stitches are used for plastic eye surgery.
When plastic eye surgery involves the lower eyelid, incisions are made along the line of the eyelashes and smile creases.
An unnaturally puffy eyelid can be corrected through transconjunctival blepharoplasty, by which excess fat is trimmed. In this procedure, the incision is made inside the lower eyelid. The stitches used in transconjunctival blepharoplasty cannot be seen by the naked eye and dissolve by themselves leaving no scar. This procedure can take anywhere from 1 to 2 hours.
Limits of Plastic Eye Surgery
This type of surgery does not remove fine lines and crow's feet. A separate, skin surface treatment that can enhance your skin's elasticity is an added option.
Unless plastic eye surgery involves a brow lift, it will not help the appearance of a sagging brow. Nor will it eliminate dark circles from under your eyes (for which topical applications exist in the market).
Your plastic surgeon will probably suggest added procedures to enhance your overall look.
Safety Issues
Serious complications from plastic eye surgery are rare. However, the occasional infection or allergic reaction to anesthetics has been known to happen. But the chances of this taking place are drastically minimized by pre-op examination of the patient's medical history, current medication, and preexisting allergies.
Some patients have been known to experience difficulty in closing their eyes, which condition is however generally not permanent.
Bruising, swelling, and redness are typical side effects of any type of plastic surgery, but none of these are permanent and will usually disappear within 10 days.
Plastic eye surgery is more risky for people certain conditions, such as:
Diabetes
Glaucoma and other eye diseases
Heart disease
High blood pressure
Hypothyroidism
Prices
For plastic eye surgery involving the upper eyelid, surgeons may charge in the area of $1,800 to $2,000. For procedures involving the upper and lower eyelids, prices may go as high as $4,500, or more depending on additional costs of anesthetics, medicine, facilities, staff, etc.
Health insurance does not usually cover any kind of cosmetic surgery. However, if plastic eye surgery is done to improve vision (as in the case where the area over the eye droops down to obstruct vision), then your expenses may be reimbursed in whole or in part.
Risks of Having Lasik Eye Surgery Problems
The probability of LASIK eye surgery problems went from 5% in the late-90s to less than 1% today. And technology isn't necessarily the reason.
Ophthalmology experts say the main reason for this is that a surgeon's success rate has been shown to naturally rise the more LASIK procedures he performs.
Complications approach zero for many qualified surgeons now that laser eye surgery is one of the most commonplace clinic based procedures. All an experienced surgeon has to do to achieve a 100% success rate is to carefully select candidates for surgery.
IK Eye Surgery Problems - Can They Be Fixed?
Say you're one of the very, very few that do experience complications after laser vision correction surgery. Will it be hard for you to have the problem fixed?
No. Even when the unlikely happens and LASIK eye surgery problems occur, they can be fixed by re-treatment or enhancement. Almost all the best surgeons offer a guarantee that, if you experience complications within a year after surgery, any additional treatments will be given to you absolutely free.
With the expertise available in America today, it will be rare indeed for LASIK surgery to result in permanent, substantial vision loss so that you're eyesight with lenses becomes poorer than before treatment.
The only way this can happen is if the person who performs your laser eye surgery lacks the credentials to do so. To make sure that your eyes are safe, go only to a Board-certified eye surgeon.
IK Eye Surgery Problems - How Can Technology Help?
Aside from picking the right surgeon, another good way of troubleshooting laser eye surgery problems is by selecting the kind of procedure you'll have done.
One of the most common problems with LASIK a few years back had to do with the cutting of the corneal flap. In LASIK, the eye surgeon creates a flap, after which he reshapes the cornea with a laser, and then returns the flap back to sort of serve as a natural bandage.
It used to be that the only way to do this would be using a microkeratome, which is a very fine metal blade with suction. If the flap is cut too thickly or too thinly, or if the flap wrinkles when it is returned, problems occur. But today, even the cutting of the corneal flap can be done with a laser.
The technology for flap creation via laser is marketed under the brand name IntraLase. Although a skilled surgeon can achieve an almost 100% success rate with a microkeratome, studies show that using a laser to create the flap has nearly eliminated complaints among LASIK patients.
Using a laser on the corneal flap increases accuracy so that defects, such as nighttime haloes, are pretty much eliminated. This option is, of course, more expensive.
Ophthalmology experts say the main reason for this is that a surgeon's success rate has been shown to naturally rise the more LASIK procedures he performs.
Complications approach zero for many qualified surgeons now that laser eye surgery is one of the most commonplace clinic based procedures. All an experienced surgeon has to do to achieve a 100% success rate is to carefully select candidates for surgery.
IK Eye Surgery Problems - Can They Be Fixed?
Say you're one of the very, very few that do experience complications after laser vision correction surgery. Will it be hard for you to have the problem fixed?
No. Even when the unlikely happens and LASIK eye surgery problems occur, they can be fixed by re-treatment or enhancement. Almost all the best surgeons offer a guarantee that, if you experience complications within a year after surgery, any additional treatments will be given to you absolutely free.
With the expertise available in America today, it will be rare indeed for LASIK surgery to result in permanent, substantial vision loss so that you're eyesight with lenses becomes poorer than before treatment.
The only way this can happen is if the person who performs your laser eye surgery lacks the credentials to do so. To make sure that your eyes are safe, go only to a Board-certified eye surgeon.
IK Eye Surgery Problems - How Can Technology Help?
Aside from picking the right surgeon, another good way of troubleshooting laser eye surgery problems is by selecting the kind of procedure you'll have done.
One of the most common problems with LASIK a few years back had to do with the cutting of the corneal flap. In LASIK, the eye surgeon creates a flap, after which he reshapes the cornea with a laser, and then returns the flap back to sort of serve as a natural bandage.
It used to be that the only way to do this would be using a microkeratome, which is a very fine metal blade with suction. If the flap is cut too thickly or too thinly, or if the flap wrinkles when it is returned, problems occur. But today, even the cutting of the corneal flap can be done with a laser.
The technology for flap creation via laser is marketed under the brand name IntraLase. Although a skilled surgeon can achieve an almost 100% success rate with a microkeratome, studies show that using a laser to create the flap has nearly eliminated complaints among LASIK patients.
Using a laser on the corneal flap increases accuracy so that defects, such as nighttime haloes, are pretty much eliminated. This option is, of course, more expensive.
Creating the Corneal Flap
LASIK is a two step procedure. In the first step, an instrument called a microkeratome lifts a thin surface layer of the cornea away from underlying layers in a process known as making a corneal flap.
Flap creation begins with the instillation of anesthetic eye drops. A suction ring is then centered around the cornea and a vacuum is generated to hold the ring on the eye. During the few seconds the vacuum is on, the vision grows dim and a mild pressure sensation is felt.
The microkeratome is then attached to the suction ring and passed across the surface of the cornea to create the flap.
Flap creation begins with the instillation of anesthetic eye drops. A suction ring is then centered around the cornea and a vacuum is generated to hold the ring on the eye. During the few seconds the vacuum is on, the vision grows dim and a mild pressure sensation is felt.
The microkeratome is then attached to the suction ring and passed across the surface of the cornea to create the flap.
LASIK - Price
LASIK (Laser-Assisted In Situ Keratomileusis) for $499? Too good to be true? Yes, according to Robert Maloney, M.D., a spokesman for the American Academy of Ophthalmology, and also director at Maloney Vision Center in LA. When the LASIK eye surgery price falls as low as $499 to $999 an eye, Maloney says that the clinic is probably cutting corners just to cut the price.
In exchange for their bargain basement prices, Maloney says the patient may be getting inferior equipment, a neophyte surgeon, faulty eye measurements, and deficient sterilization techniques.
What You Are Paying For?
An extremely low LASIK eye surgery price can mean ineffective surgery that will end up with you spending more to have a better surgeon repeat the procedure.
At worst, an insufficient LASIK eye surgery price can mean damage to your eye due to complications, such as infection, scarring, and serious injury to your cornea.
When you pay an amount within the LASIK eye surgery price range of a reputable clinic or surgeon, $1,500 to $2,500 per eye, you pay, first of all, for the surgeon’s experience. A surgeon's LASIK eye surgery experience generally decreases complications.
Although complications have been observed in less than 1% of LASIK cases, one study reports that complications are likely to be less after a surgeon has performed 1,000 LASIK procedures.
Aside from your surgeon’s skill, the LASIK eye surgery price also includes:
Purchase/lease/maintenance of laser equipment
Purchase of microkeratome, corneal ring segments, and other gadgets
Royalties to laser manufacturer (to recoup high cost of developing cutting-edge technology)
$100 to $150 an eye, for regular excimer laser
$145 to $250 an eye, for custom procedures
Cost of keeping the LASIK eye surgery sterile
Gloves, gowns, masks
Surgical solutions, medications
Overhead costs of the center or clinic
Rent
Utilities
Office equipment, supplies
Office and staff salaries, benefits
Marketing costs
Website fees
Advertisements
Seminars
Insurance
Professional fees
Co-management fees for other practitioners
Surgeon’s fee (especially if not on staff)
Evaluation, follow-up exams
Comprehensive eye exams
Technician
Equipment
Medications
Financing
Rather than settling for a rock bottom LASIK eye surgery price and putting your vision in jeopardy, it is wiser to pick a reputable surgeon and find a way to help finance your surgery.
Many good LASIK eye surgery centers offer financing plans to their patients. And although insurance plans normally do not cover LASIK eye surgery since it is regarded as a cosmetic procedure, employers can make an arrangement with a LASIK center for a special price for employees.
In exchange for their bargain basement prices, Maloney says the patient may be getting inferior equipment, a neophyte surgeon, faulty eye measurements, and deficient sterilization techniques.
What You Are Paying For?
An extremely low LASIK eye surgery price can mean ineffective surgery that will end up with you spending more to have a better surgeon repeat the procedure.
At worst, an insufficient LASIK eye surgery price can mean damage to your eye due to complications, such as infection, scarring, and serious injury to your cornea.
When you pay an amount within the LASIK eye surgery price range of a reputable clinic or surgeon, $1,500 to $2,500 per eye, you pay, first of all, for the surgeon’s experience. A surgeon's LASIK eye surgery experience generally decreases complications.
Although complications have been observed in less than 1% of LASIK cases, one study reports that complications are likely to be less after a surgeon has performed 1,000 LASIK procedures.
Aside from your surgeon’s skill, the LASIK eye surgery price also includes:
Purchase/lease/maintenance of laser equipment
Purchase of microkeratome, corneal ring segments, and other gadgets
Royalties to laser manufacturer (to recoup high cost of developing cutting-edge technology)
$100 to $150 an eye, for regular excimer laser
$145 to $250 an eye, for custom procedures
Cost of keeping the LASIK eye surgery sterile
Gloves, gowns, masks
Surgical solutions, medications
Overhead costs of the center or clinic
Rent
Utilities
Office equipment, supplies
Office and staff salaries, benefits
Marketing costs
Website fees
Advertisements
Seminars
Insurance
Professional fees
Co-management fees for other practitioners
Surgeon’s fee (especially if not on staff)
Evaluation, follow-up exams
Comprehensive eye exams
Technician
Equipment
Medications
Financing
Rather than settling for a rock bottom LASIK eye surgery price and putting your vision in jeopardy, it is wiser to pick a reputable surgeon and find a way to help finance your surgery.
Many good LASIK eye surgery centers offer financing plans to their patients. And although insurance plans normally do not cover LASIK eye surgery since it is regarded as a cosmetic procedure, employers can make an arrangement with a LASIK center for a special price for employees.
Astigmatism
Astigmatism causes light entering the eye at different axes to be focused different amounts. For example, light entering vertically (from 12 o'clock to 6 o'clock) may be focused more than light entering horizontally (from 9 o'clock to 3 o'clock). In an eye without astigmatism, light is focused the same amount in each axis.
The net result of astigmatism is blurred vision. Often letters appear slanted or with "tails" coming off of them. Sometimes the affected eye sees double.
When LASIK is performed for astigmatism, the cornea is reshaped by the laser to allow proper focusing, regardless of the axis light enters the eye. In practical terms, astigmatism is treated similar to nearsightedness and farsightedness, but with different amounts of treatment to each axis.
yperopia
Farsightedness
With hyperopia, the cornea does not bend incoming light enough, so light focuses behind the retina.
Hyperopia causes blurry vision up close and at distance. Hyperopia must be distinguished from presbyopia, which is clear vision at distance with a need for reading glasses up close.
When LASIK is performed for hyperopia, the corneal surface is gently steepened by the laser, resulting in more bending of incoming light and proper focusing on the retina.
With hyperopia, the cornea does not bend incoming light enough, so light focuses behind the retina.
Hyperopia causes blurry vision up close and at distance. Hyperopia must be distinguished from presbyopia, which is clear vision at distance with a need for reading glasses up close.
When LASIK is performed for hyperopia, the corneal surface is gently steepened by the laser, resulting in more bending of incoming light and proper focusing on the retina.
Myopia
Nearsightedness
With myopia, the cornea is too steeply curved and too much focusing power is produced. This makes distant objects blurry, because light is focused in front of the retina. Near objects remain clear.
When LASIK is performed for myopia, the laser gently flattens the cornea, which lessens the bending of incoming light, thereby allowing it to focus on the retina.
With myopia, the cornea is too steeply curved and too much focusing power is produced. This makes distant objects blurry, because light is focused in front of the retina. Near objects remain clear.
When LASIK is performed for myopia, the laser gently flattens the cornea, which lessens the bending of incoming light, thereby allowing it to focus on the retina.
Retinal Surgery
Retinal surgery generally deals with reattaching the retina when it is pulled or torn from its normal position. The retina lies in back of the eye, sending visual information via the optic nerve up to the brain. If breaks or holes occur along this connection, it may cause total blindness.
Retinal detachment can occur at any age for any number of reasons. However, the condition is most common around midlife or later. Retinal detachment is sometimes caused by an age-related shrinking of the eye's gelatinous contents (called vitreous) away from the surface, leading to a tear.
Some of other factors that increase the likelihood of a detached retina are:
Severe physical trauma
Ocular infection or inflammation
A previous cataract operation
Glaucoma
Nearsightedness
A preceding retinal detachment in the other eye
Family history of detached retinas
Weak retinal areas (can be detected by an ophthalmologist during eye exams)
Some retinal detachments are caused by diabetes or abnormalities in the development of the eye.
Preventive Measures
If you experience visual disturbances, such as dark spots, light flashes, and wavy or blurry vision, consult your ophthalmologist immediately. Retinal detachment is a serious, but easily treated condition.
However, prompt corrective surgery is crucial to preventing permanent damage to your vision. If left alone too long, retinal detachment can lead to your complete blindness or the shrinking of your eye.
That is why it is essential to have regular checkups with your ophthalmologist. More often than not, the weakness and vulnerability of the retina can be detected through eye exams.
When retinal detachment is confirmed, you will undergo several exams (e.g., opthalmoscopy, ultrasound) to determine which type of retinal surgery best suits your condition.
Risks in Retinal Surgery
There is no other alternative for repairing a detached retina but surgery. But just like any medical procedure, retinal surgery involves risks, such as:
Bleeding
Cataract
Infection
Pressure inside eye
Retinal surgery is a common procedure and is usually successful. However, a second surgery may be needed.
If the retina cannot be reconnected by retinal surgery, vision will become continually poorer until the eye becomes totally blind.
Benefits of Retinal Surgery
The foremost benefit is, of course, you will not lose your vision. Depending on the extent of the tear, it may take months for vision to improve. In certain cases, vision is never fully restored to the way it was originally.
This is the reason why early detection is crucial. Some patients with chronic retinal detachment still do not regain any vision despite retinal surgery.
Belated surgery may not do you any good because the more badly torn the retina is and the longer the tear has been present, the less likely it is that vision will return.
Visit your ophthalmologist the minute you experience any unusual visual symptoms.
Retinal detachment can occur at any age for any number of reasons. However, the condition is most common around midlife or later. Retinal detachment is sometimes caused by an age-related shrinking of the eye's gelatinous contents (called vitreous) away from the surface, leading to a tear.
Some of other factors that increase the likelihood of a detached retina are:
Severe physical trauma
Ocular infection or inflammation
A previous cataract operation
Glaucoma
Nearsightedness
A preceding retinal detachment in the other eye
Family history of detached retinas
Weak retinal areas (can be detected by an ophthalmologist during eye exams)
Some retinal detachments are caused by diabetes or abnormalities in the development of the eye.
Preventive Measures
If you experience visual disturbances, such as dark spots, light flashes, and wavy or blurry vision, consult your ophthalmologist immediately. Retinal detachment is a serious, but easily treated condition.
However, prompt corrective surgery is crucial to preventing permanent damage to your vision. If left alone too long, retinal detachment can lead to your complete blindness or the shrinking of your eye.
That is why it is essential to have regular checkups with your ophthalmologist. More often than not, the weakness and vulnerability of the retina can be detected through eye exams.
When retinal detachment is confirmed, you will undergo several exams (e.g., opthalmoscopy, ultrasound) to determine which type of retinal surgery best suits your condition.
Risks in Retinal Surgery
There is no other alternative for repairing a detached retina but surgery. But just like any medical procedure, retinal surgery involves risks, such as:
Bleeding
Cataract
Infection
Pressure inside eye
Retinal surgery is a common procedure and is usually successful. However, a second surgery may be needed.
If the retina cannot be reconnected by retinal surgery, vision will become continually poorer until the eye becomes totally blind.
Benefits of Retinal Surgery
The foremost benefit is, of course, you will not lose your vision. Depending on the extent of the tear, it may take months for vision to improve. In certain cases, vision is never fully restored to the way it was originally.
This is the reason why early detection is crucial. Some patients with chronic retinal detachment still do not regain any vision despite retinal surgery.
Belated surgery may not do you any good because the more badly torn the retina is and the longer the tear has been present, the less likely it is that vision will return.
Visit your ophthalmologist the minute you experience any unusual visual symptoms.
Tuesday, March 17, 2009
Horizon Advantage - Laser
Horizon Laser Vision Center uses the most advanced VISX Star S4™ Excimer Laser, the CustomVue, for both LASIK and PRK. This laser utilizes the latest technology currently available, which translates into greater accuracy of treatments, safety and improved visual outcomes. View an animation of the CustomVue procedure.
The VISX Star S4™ Excimer Laser System is a computer-assisted surgeon-controlled device that includes WaveScan® and ActiveTrak® devices combined with Variable Spot Scanning (VSS®) technology in addition to excimer lasers.
Excimer lasers are cool concentrated beams of ultraviolet light that safely, painlessly evaporate microscopic layers of the cornea leaving the underlying tissue virtually untouched.
The WaveScan uses light wave technology to identify and measure imperfections in an individual's eye 25 times more accurately than standard methods used for glasses and contact lenses. These measurements are used to individually customize laser vision correction. The WaveScan produces a WavePrint Map®, which is a visual representation of how a patient's entire optical system processes light. This map is much like a fingerprint - no two are alike. It allows for a more precise and detailed analysis of a patient's vision and is used by the ophthalmologist to ensure optimal treatment results.
ActiveTrak™ 3D Eye Tracker follows the tiny motions of your eye instantaneously and automatically, in all three dimensions, continually repositioning the laser to ensure accuracy. Without a tracking device, laser vision correction requires patients to hold their eyes as still as possible during the procedure. However, even a 'still' eye makes minute, involuntary movements - including moving slightly with each breath. With 3D ActiveTrak, you can relax during your laser vision correction, knowing the procedure will be delivered with precision and accuracy.
Variable Spot Scanning* (VSS™) is an exclusive VISX laser technology that allows for a larger treatment area. This offers the ophthalmologist greater flexibility in developing a more personalized laser vision procedure. It adjusts the laser beam size according to the treatment, minimizing corneal tissue removal. This also allows for quicker treatment times that are typically between 10 to 40 seconds. Variable Spot Scanning technology adds a blend zone that allows the treatment on the cornea to be extended to 8 mm which may help reduce the risk of night vision symptoms in certain patients.
The VISX laser has been used to perform over 5 million procedures globally. Visit the VISX web site to learn more about this advanced technology.
The VISX Star S4™ Excimer Laser System is a computer-assisted surgeon-controlled device that includes WaveScan® and ActiveTrak® devices combined with Variable Spot Scanning (VSS®) technology in addition to excimer lasers.
Excimer lasers are cool concentrated beams of ultraviolet light that safely, painlessly evaporate microscopic layers of the cornea leaving the underlying tissue virtually untouched.
The WaveScan uses light wave technology to identify and measure imperfections in an individual's eye 25 times more accurately than standard methods used for glasses and contact lenses. These measurements are used to individually customize laser vision correction. The WaveScan produces a WavePrint Map®, which is a visual representation of how a patient's entire optical system processes light. This map is much like a fingerprint - no two are alike. It allows for a more precise and detailed analysis of a patient's vision and is used by the ophthalmologist to ensure optimal treatment results.
ActiveTrak™ 3D Eye Tracker follows the tiny motions of your eye instantaneously and automatically, in all three dimensions, continually repositioning the laser to ensure accuracy. Without a tracking device, laser vision correction requires patients to hold their eyes as still as possible during the procedure. However, even a 'still' eye makes minute, involuntary movements - including moving slightly with each breath. With 3D ActiveTrak, you can relax during your laser vision correction, knowing the procedure will be delivered with precision and accuracy.
Variable Spot Scanning* (VSS™) is an exclusive VISX laser technology that allows for a larger treatment area. This offers the ophthalmologist greater flexibility in developing a more personalized laser vision procedure. It adjusts the laser beam size according to the treatment, minimizing corneal tissue removal. This also allows for quicker treatment times that are typically between 10 to 40 seconds. Variable Spot Scanning technology adds a blend zone that allows the treatment on the cornea to be extended to 8 mm which may help reduce the risk of night vision symptoms in certain patients.
The VISX laser has been used to perform over 5 million procedures globally. Visit the VISX web site to learn more about this advanced technology.
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