PRK, more commonly known as 'refractive lens exchange', is an alternative to LASIK. Like LASIK, it improves vision by reshaping the cornea; but unlike LASIK, it does not create a flap in the cornea, which means more of the corneal tissue is preserved. PRK has been around for many years and was used extensively prior to the introduction of LASIK. Today, it's most often used in patients for whom LASIK is not an ideal procedure.
PRK can treat the same types of conditions as LASIK, including myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.
Both PRK and LASIK offer similar visual outcomes, but healing following PRK is generally a little slower than LASIK. PRK is also associated with a slightly higher risk of infection and hazy vision right after treatment, and LASIK generally results in less discomfort during the initial stages of healing. LASIK patients also tend to achieve visual stability more quickly than people who have PRK. However, PRK offers significant benefits for patients with thin corneas and for those who have undergone LASIK procedures in the past because it preserves more of the corneal tissue. Plus, because PRK doesn't create a flap in the cornea, there's no risk of flap-related complications and the risk of removing too much of the cornea (overcorrecting) is also reduced.
PRK begins by gently removing the central portion of the corneal coating, or epithelium, using a special solution or a surgical device. Once the epithelium is removed, a laser is used to gently remove microscopic amounts of the corneal tissue so it can be reshaped. A special contact lens will be placed on your eye to protect the cornea while new epithelial cells form, a process that takes several days.