CELL MIGRATION AND PROLIFERATION DURING REPAIR OF SUPERFICIAL CORNEAL WOUNDS PRODUCED BY A CARBON DIOXIDE LASER

Superficial wounds were produced in the rabbit corneal epithelium by a 2-mm. circular beam from a carbon dioxide laser. The healing response of the epithelium was examined histologically in tritiated thymidine radioautographs at various times following wounding. Proliferation activity and cell population per unit length were recorded in the basal cell layer proceeding outward from the wound center. Profiles of the basal cell migration, density, and proliferative pattern were graphically constructed from averaged numerical tabulations of individual wounds. The observed rates of basal cell synthesis of DNA were found to be much higher in areas where active migratory repopulation of the wound site was occurring than in undisturbed epithelium. These findings are contrary to results of other investigators who have studied healing responses in deeper corneal wounds. The difference is attributed to preservation of the epithelial basement lamina in the superficial wounds. The proliferative patterns found were characterized by one or more pronounced peaks of activity, and these were related to depressions in the basal cell population density resulting from rapid cell migration into the wound area. (Author)