ABSTRACT
Manual epithelial debridement was found to produce scratches and nicking in the Bowman’s layer and to leave variable amounts of epithelium (1,2). Chemical agents like 0.5% proparacaine iodine, cocaine, alkali n-heptanol, and ethanol have been used to remove the corneal epithelium in experimental studies (3,4). Currently, 18% to 20% ethanol is commonly used in laser subepithelial keratomileusis (LASEK). However, it is potentially toxic to the corneal tissue. The use of 100% ethanol for 2 minutes on rabbit corneas lead to a significant decrease in stromal keratocytes after 24 hours (4). Similarly, when using 70% isopropyl alcohol for 2 minutes for epithelium removal in rabbit eyes, Agrawal et al. found an increased inflammatory response and damaging effect on keratocytes (5). Helena et al. observed increased keratocyte loss but decreased inflammation after using 50% ethanol for 1 minute compared to mechanical debridement (6). Indeed, the toxic effect of alcohol on epithelial cells has been used for therapeutic purposes. For example, 50% ethanol was reported in the treatment of progressive or recurrent epithelial in-growth after laser in situ keratomileusis (LASIK) (7).
