Corneal Epithelial and Stromal Reactions to Excimer Laser Photorefractive Keratectomy

From the perspective of an epithelial cell biologist, I have several concerns regarding healing of the epithelium after excimer laser ablation for change of corneal refraction. One concern is the hyperplastic response of the epithelium when a wound is made in the stroma. The preexisting curvature of the cornea is restored in such wounds by increased layers of epithelial cells. 1-3 If such a response occurs after ablation, the optical effect of the surgery would be unstable and would regress. Anecdotal statements by some investigators using laser ablation as a technique of refractive surgery indicate that if the edge of the area tapers gradually toward the deepest ablation zone, the hyperplastic response does not occur. Such preliminary observations need to be documented by careful animal studies. A second concern is that ablation of the anterior stroma removes the basement membrane and the anchoring fibril network, structures that are needed for