In PRK, topical anesthesia is applied to the surface of the eye. Next, the surgeon removes the central epithelium of the cornea by one of a variety of different means. Then, the surgeon uses an excimer laser to treat the exposed corneal tissue, thereby changing its shape in a very precise manner to correct the refractive error. Once this is accomplished, the surgeon places a bandage contact lens on the cornea and the epithelium heals under it over the next 2 to 4 days.
Your surgeon can explain the limits of refractive errors that can be treated by PRK.
Not every patient is a candidate for PRK. Patients with thin corneas, progressive ectasia, scars, irregular astigmatism, and a few other pathologies are ineligible. Your surgeon, or one of the optometrists in his or her practice, can determine if you are a suitable candidate during a free screening examination.
PRK typically takes 10 to 15 minutes to perform and usually only one eye undergoes surgery at a time, although there are exceptions. PRK is associated with minimal to mild discomfort while it is being performed. When the topical anesthesia wears off, however, the level of discomfort increases significantly. Most patients develop redness and tearing. There is often stinging and a gritty sensation that lasts 3 to 4 days. The bandage contact lens is removed following corneal epithelial recovery. Visual recovery takes 3 to 4 weeks.
As with any procedure, there is a risk of complications with PRK, including the possibility of an under correction or over correction. The risks should be discussed with your doctor before you undergo the procedure.