Keratoprosthesis. Implantation of artificial corneas.

Keratoprosthesis (implantation of artificial, plastic cornea) is indicated in severe cases with corneal leucoma (non-transparent, cicatrized cornea) in which keratoplasty (corneal transplantation) is not possible or has repeatedly failed. In the past 40 years we implanted 37 artificial corneas (7 Cardona type, 29 Konstantinov type, 1 Fjodorov type). The visual acuity increase was temporary (lasting from a few weeks to a few months) in 25 patients. The visual acuity was at least 0.2 three years following the implantation of keratoprosthesis in 12 patients. One patient had 1.0 vision 10 years after surgery. Our results indicate that the implantation of artificial corneal is still an "ultimum refugium", an operation that can be justified only in monocular patients, in eyes that cannot be and/or had unsuccessfully been operated on with repeated keratoplasties. The visual improvement is temporary, but in some cases may last for several years. Still this is the only procedure by which useful vision can be provided, for shorter or longer time intervals, for patients suffering from corneal blindness (nontransparent cornea in otherwise functioning eye) whose only eye cannot be treated with corneal transplantation. Keratoprosthesis with better biocompatibility, better fixation techniques, and wider visual fields have to be developed before the implantation of artificial cornea can be looked upon as a surgical procedure with which full optical rehabilitation can be achieved.