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PURPOSE The corneal epithelium is generally removed before photoablation in photorefractive keratectomy (PRK) because laser transepithelial PRK may result in surface irregularity caused by variability in epithelial thickness and differing ablation rates between epithelium and stroma. We compared the effects of mechanical deepithelialization with chemical epithelial removal by using 50% ethanol on the corneal structure. METHODS Fourteen rabbits underwent corneal deepithelialization by using a blade in the left eye and 24 h later in the right eye. Another 14 rabbits underwent corneal deepithelialization by using 50% ethanol solution. Half of the eyes treated with each technique underwent PRK after deepithelialization. Pachymetry was performed before and after each procedure on right eyes. Keratocyte and neutrophil densities were assessed by light microscopy. RESULTS Among non-laser-treatment groups, eyes that underwent mechanical deepithelialization had decreased corneal thickness (p = 0.001), increased keratocyte densities (p = 0.03), and no significant difference in neutrophil densities (p = 0.91) compared with chemically treated eyes 24 h after surgery. Among laser-treatment groups, eyes that underwent mechanical epithelial removal had increased keratocyte densities (p = 0.001), decreased corneal thickness (p = 0.03), and increased neutrophil densities (p = 0.03) 24 h after surgery compared with chemically treated eyes. CONCLUSION Deepithelialization with 50% ethanol causes more keratocyte loss with perhaps more corneal edema, but less stromal influx of neutrophils, than does a mechanical technique 24 h after PRK in a rabbit model. Corneal deepithelialization with dilute ethanol may be a viable option in PRK. However, further investigation into the safety of this technique is warranted before it can be widely applied clinically.

Purpose To report the occurrence and follow-up of ec-topic, interface, epithelial growth after laser in situ keratomileusis (LASIK) in four eyes (three patients) and provide suggestions for management. Methods Each eye was examined by slit-lamp biomicroscopy, and corneal topography was obtained with the Tomey TMS-1 instrument. Results Each eye with epithelium within the interface after LASIK developed interface opacities and surface irregularity. One eye had an early surgical intervention, and three eyes were observed. Each eye lost at least one line of best spectacle-corrected visual acuity and had visual disturbance at the last follow-up visit. Conclusions The presence of epithelium within the lamellar interface is a significant complication after LASIK. In some cases, interface epithelium may be associated with early postoperative inflammation. When reoperation is required to treat this complication, we suggest scraping of both sides of the interface with a metal blade. In some cases, light excimer laser treatment can be used to facilitate epithelial removal.