Sessile macrophages forming clear endotheliumlike membrane on the inside of successful keratoprosthesis.

Clinical observation and cytological study of a successful "through and through" type of Cordona keratoprosthesis, which was removed along with a corneal button about 20 years after its implantation in an aphakic eye, revealed an acellular epitheliumlike film on its outer surface, firm anchoring of its supporting skirt by stable fibrous connections to the stroma, and a continuous separating membrane composed of a homogeneous proteinaceous film with fibroblastlike cells of macrophage origin on its inner surface. The significance of the successful adaptation of the plastic materials of the prosthesis to the tissues of the cornea and the fluid of the inner eye for the future of tissue engineering is discussed.