Factors affecting the outcome of corneal transplantation.

Corneal grafting has been attempted for 200 years. Greatly improved results in recent years have been attributed to developments in anaesthesia, asepsis, and immunological and anti-inflammatory therapy. The important factors affecting the outcome of corneal grafting today are the degree of vascularisation of the cornea before surgery, the inflammatory status at the time of surgery, and the number of antigenic determinants shared by donor and host. Allograft rejection is the most common cause of corneal graft failure. Animal experiments suggest that cyclosporin A given at the time of surgery is likely to prove the most effective means available for preventing corneal graft rejection. Although the introduction of more specific immunosuppressive agents is important, the development of techniques to improve the environment of the outer eye demands the highest priority. Corneal disease is the commonest cause of blindness on a world scale, but many patients are unacceptable for grafting with the currently accepted criteria for operability.