Comparison of Benefits and Risks of LASIK to PRK

(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.