Photorefractive Keratectomy (PRK) : Comparison of Corneal Haze Between Two Modes of De-epithelialisation (Laser Versus Manual Alcohol)

A Merocel sponge is soaked in a saline solution to expand before being gently applied to the corneal surface in three gestures similar to painting. This standardised procedure avoids inhomogeneous wetting of the cornea, which would result in uneven ablation. The laser ablation is then performed.

A ring is placed in the centre of the cornea and filled with 20% alcohol. After 20 seconds of exposure, the alcohol is absorbed with a small sponge and the corneal epithelium is debrided with a polyvinyl alcohol expanding sponge (Merocel, Medtronic). The entire cornea is rinsed with balanced salt solution and the epithelium is peeled away from the corneal stroma. The corneal bed is then dried with a small sponge and laser ablation is performed.