Mechanical vs. alcohol epithelial removal during photorefractive keratectomy

Abstract

Purpose: To assess whether a chemical debridement method for excimer laser photorefractive keratectomy may lead to better refractive and visual results than the standard method which involves the use of a blunt blade to scrape off the epithelium.

Methods: Ninety-three eyes with a mean attempted correction of -5.72 +/- 2.47 D were debrided using a surgical microsponge after epithelial melting by 20% ethanol solution applied for 20 seconds, and treated by PRK. Results were compared to those from 97 eyes with a mean attempted correction of -6.05 +/- 2.46 D, deepithelialized using a Desmarres blade.

Results: Debridement time was faster in the eyes where alcohol was used (P = .04). During a 6-month follow-up, we found no significant differences in refractive error, uncorrected, and spectacle-corrected visual acuity. However, haze rates at were lower (1 month, P = .04), and corneal regularity index was better (3 months, P = .01) in the eyes deepithelialized using alcohol.

Conclusions: Epithelial debridement using a 20% alcohol solution was faster to perform, and provided sharper edges and a smoother Bowman's layer surface than mechanical debridement. This may explain the better results in terms of haze and corneal regularity.