INCORPORATION OF A FLUOROCARBON POLYMER IMPLANTED AT THE POSTERIOR SURFACE OF THE RABBIT CORNEA

An implant of porous expanded polytetrafluoroethylene (PTFE) in the co rneal stroma allows fast cell colonization and can become translucent. We studied the behavior of the same polymer implanted in the anterior chamber of the rabbit eye and sutured to the posterior surface of the cornea. The expanded tetrafluoroethylene was provided as 200-micron t hick sheets in 3 pore diameters (20, 50, and 80 microns). Disks (5 mm) were implanted in the anterior chambers of 20 rabbits and sutured to the posterior surface of the cornea. Histological and ultrastructural studies were performed after 3 and 4 months. Quantimetry was done on T EM images to analyze the fibrillar structure of the intercellular mati x inside and around the implanted polymer. The material was well toler ated. In all cases there was mild central corneal edema, which disappe ared after 1 month. Mild neovascularization occurred in five cases, de creasing after 1 month. The polymer became translucent after 8 days. K eratocytes from the corneal stroma colonized the implant via breaks in the Descemet's membrane along the sutures. Quantimetry showed three t ypes of fibrils inside and beside the polymer. Corneal endothelial cel ls regenerated over the fibroblasts and the polymer. This fluorocarbon polymer implanted in the anterior chamber and sutured to the posterio r surface of the cornea was well tolerated, and there was real incorpo ration, with keratocytes producing collagen fibrils inside the polymer and endothelial cells forming a posterior cell monolayer. This is pro mising for the development of a keratoprothesis with posterior fixatio n. (C) 1996 John Wiley & Sons, Inc.