IN-VIVO EVALUATION OF A COLLAGEN CORNEAL ALLOGRAFT DERIVED FROM RABBIT DERMIS

BACKGROUND: This study evaluates epithelialization, clarity, intraocul ar inflammation, and fibroblast ingrowth of a collagen corneal allogra ft derived from rabbit dermis. METHODS: Dermal collagen fibers were di spersed intact and chemically modified to make them soluble. The allog rafts consisted of a fibrous, opaque peripheral zone and a central cle ar area. Twelve New Zealand white rabbits underwent penetrating kerato plasty with implantation of an allograft. The grafts were evaluated da ily for clarity, anterior segment inflammation, and extent of reepithe lialization with a slit-lamp microscope. RESULTS: Epithelialization of the fibrous peripheral zone of the graft ranged from 0% to 90%. The c entral clear area did not epithelialize in any of the animals. Fibrobl asts migrated into the peripheral zone in all eyes. Complications incl uded ulceration of the central clear area in two eyes. There was no ul ceration or leakage at the graft-host interface and no synechia, fibro us, or inflammatory retrocorneal membranes in any of the eyes. CONCLUS IONS: Our study is the first to describe the method of modifying derma l type I collagen into a clear corneal allograft. Survival of the corn eal collagen allograft beyond 1 month may be limited by several factor s including lack of epithelialization of the central clear area.