PRK (or PhotoRefractive Keratectomy) is a procedure that corrects nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. It utilizes the Excimer Laser, the same laser that is used to perform LASIK surgery. The two procedures provide similar results with respect to vision and long term stability. Other procedures known as LASIK or Advanced Surface Ablation are very similar if not equivalent to PRK. These procedures differ from LASIK in the way they are performed, and in terms of recovery and healing. The final vision results however are usually equivalent. PRK is often performed in patients who are candidates for refractive surgery, but are unable to have LASIK because of thin or atypically shaped corneas, or lifestyle requirements.
The PRK procedure begins by removing the top layer of cells from the cornea called the epithelium. The epithelium is equivalent to skin elsewhere in the body except that it is transparent to allow vision. The epithelium regrows or regenerates after a few days. After the epithelium is removed at the start of the procedure, the Excimer Laser is used to reshape the cornea as needed to correct your prescription. After completion of the laser, a special antibiotic agent called Mitomycin C may be applied to the cornea to prevent the later development of scar tissue. Then, a specially designed bandage contact lens is applied to the cornea to protect the surface of the eye as it heals. This contact lens is typically left in place for several days until the corneal epithelium has regrown, as mentioned above. During this period, medicated eye drops are used, and mild to moderate irritation of the eyes is experienced, along with blurring of vision. These symptoms are typically not severe, and usually do not interfere with daily activities. It is very important however to avoid getting water and irritants into the eye during this initial stage of healing. During the next stage of healing, which usually lasts about 4-6 weeks, the eyes are typically comfortable but may feel dry at times. Frequent use of artificial tears is recommended. Your vision may fluctuate during this period, but will typically stabilize at around 2-3 months after the procedure.