Photorefractive Keratectomy (PRK)
Photorefractive keratectomy (PRK) is a unique laser vision correction procedure that uses an excimer laser to burn away a small amount (about 5 to 30 percent) of the top of the cornea in order to correct refractive errors. Instead of cutting a flap into the cornea with a blade like the LASIK procedure, this method preserves the strength of the cornea and avoids the risk of perforation and other flap errors commonly associated with the blade method.
The PRK procedure also provides the surgeon with greater control over the location and amount of tissue being removed, allowing patients to enjoy a much more accurate treatment. The PRK method involves gently sculpting the cornea rather than cutting, allowing your surgeon to treat greater degrees of nearsightedness, as well as farsightedness and astigmatism. Up to 95 percent of patients with a correction of up to -6.00 diopters achieved vision of 20/40 or better after PRK, with up to 70 percent achieving 20/20.
Candidates for PRK
Before LASIK was available, PRK was the most commonly performed refractive surgery procedure. LASIK brought about several advantages over PRK, including less discomfort and faster results, but PRK is still preferred for patients with large pupils or thin corneas who are not candidates for LASIK, as it maintains corneal strength while providing impressive vision correction. This procedure is also ideal for those patients who are worried about "going under the knife" during the traditional LASIK procedure.
During the PRK procedure, the eyes are numbed with anesthetic eye drops, before your doctor uses targeted laser energy to correct the shape of the cornea. The doctor has complete control over the laser throughout the procedure for highly precise, customized results designed to give each patient the best vision for their individual eyes. The entire procedure takes only a few minutes to perform in your doctor's office.
Recovery from PRK
Once the PRK procedure is completed, you will be able to go home after a few hours, although you will need someone to drive you home. A bandage contact lens will be placed over the eye to protect the surface and allow it to heal properly. This lens will likely be worn for three to four days, depending on your doctor's instructions. Patients may need to wear glasses after the procedure until vision stabilizes. Your doctor will also prescribe eye drops to prevent infection and keep the eyes moisturized.
While vision may seem to have improved initially, full results may take six weeks to six months to develop. Patients may be able to return to work the next day, unless your doctor recommends resting for a few days. Strenuous exercise should be avoided for at least a week, as this can affect the healing process. You will likely be able to see well enough to drive a car after two or three weeks.
Results of PRK
The results of PRK are considered comparable to those achievable with LASIK, although some patients may experience vision of only 20/40, and others may still need glasses or contact lenses after their procedure. PRK does not correct presbyopia, a natural change in the eyes that affects everyone over the age of 40, so patients that need reading glasses will continue to need them after surgery. It is important for patients to maintain realistic expectations in order to be satisfied with the results of PRK.
Risks of PRK
As with any type of surgery, there are certain risks associated with the PRK procedure, including infection, reaction to anesthesia, undercorrection or overcorrection and sensitivity to light. These risks are considered rare and can be further reduced by choosing an experienced surgeon to perform your procedure.