PRK

Surface laser ablation, flap free vision correction

Overview

Photorefractive keratectomy, PRK, is a laser refractive surgery in which an excimer laser reshapes the surface of the cornea directly, without creating a flap. The thin epithelial layer is first removed mechanically, with dilute alcohol, or with the laser, and the exposed stroma is ablated to correct myopia, hyperopia, or astigmatism. A bandage contact lens is placed while the epithelium regrows over several days. PRK was the first excimer laser refractive procedure, developed in the 1980s, with Theo Seiler and Marguerite McDonald among those performing early treatments. Compared with LASIK, recovery is slower and more uncomfortable in the first days and vision takes longer to stabilize, but final visual results are similar. Because no flap is made, PRK avoids flap related complications and preserves more corneal thickness, so it is often chosen for people with thinner corneas or those in occupations and sports with a risk of eye injury. Corneal haze is a recognized complication after larger corrections, and the antimetabolite mitomycin C is used during surgery to reduce it.