The effect of collagen shields on rabbit corneal reepithelialization after chemical debridement.

We evaluated the effect of precarved collagen lenses on the kinetics of epithelial wound healing in an experimental model of corneal erosions. After induction of anesthesia, central corneal erosions of 5-mm diameter were created in New Zealand white rabbits using n-heptanol. Animals were randomly assigned either to the treatment group or to one of three control groups. Each animal in the treatment group received a precarved collagen shield made from porcine sclera. Immediately after creation of the corneal epithelial defects, topical fluorescein sodium was applied, and the corneas were photographed. Similar follow-up examinations were conducted at 5, 24, 30, 48, 72, and 96 hr after defect creation. Epithelial defect areas were calculated by projecting the photographic slides onto a computerized digitizing pad. Reepithelialization kinetics were compared for the four treatment groups. When initial wound size was taken into account, no significant difference between mean reepithelialization rates was noted. These results indicate that collagen lenses do not adversely affect the speed of corneal reepithelialization, and may, because of their documented biodegradibility and drug delivery capability, be useful in the clinical management of corneal epithelial erosions.