[A new concept for keratoprosthesis].

Although keratoprosthesis (after Strampelli and Cardona) is successful in selected cases, it remains doubtful whether the apparent problems of these procedures can be solved. The Cardona-Strampelli concept was therefore abandoned; a new design was evolved and new alloplastic materials were used--silicone for the optical zone and carbon fibers for the haptic part of the prosthesis. The interaction of living tissue with these alloplastic materials was investigated in tissue-culture experiments and in vivo, and indicated that the materials had excellent properties for prosthetic purposes. Stable anchorage of the implants was assured by the strong adhesion of the fibroplasts to the carbon fibers. In more than a year of observation no granulomatous reaction was observed. In animal experiments, the special design of the prosthesis-tissue interface prevented epithelial downgrowth, one of the major problems in keratoprosthesis. Moreover, a fluid-tight interaction of the alloplastic material and the tissue was achieved.