The Excimer Laser reshapes the cornea to possibly reduce or eliminate the need for glasses or contact lenses in cases of myopia (nearsightedness) or hyperopia (farsightedness) and astigmatism. The curvature of the eye must be reshaped. There are two ways it can be accomplished with the laser, on the surface with PRK (Photo Refractive Keratectomy) or beneath the surface with LASIK. The surface cells of the eye (epithelium) are more reactive; they may produce more pain, infection, and scaring. In severe cases of myopia and astigmatism where more healing complications are encountered, LASIK is the treatment of choice. By going underneath a flap of tissue with the LASIK procedure, the risk associated with healing are significantly reduced. The intraoperative risk (risks related to the surgery itself), however, are greater with LASIK than PRK alone. This is due to the use of the microkeratome (a surgical instrument much like a carpenter’s plane) in LASIK, which is not used in PRK. The disadvantages of this procedure are those associated with the microkeratome.

Photo Refractive Keratectomy (PRK) is a procedure that is approved by the FDA to treat mild to moderate degrees of myopia, hyperopia and/or astigmatism. Laser Assisted In Situ Keratomilieusis (LASIK) is a procedure approved to treat larger degrees of myopia, hyperopia, and or astigmatism using the Excimer laser and the microkeratome is also approved by the FDA.