PRELIMINARY EVALUATION OF A HYDROGEL CORE-AND-SKIRT KERATOPROSTHESIS IN THE RABBIT CORNEA

BACKGROUND: We developed a core-and-skirt keratoprosthesis, with both components made from poly(2-hydroxyethyl methacrylate) (PHEMA) hydroge ls. The identical chemical nature of both spongy skirt and transparent core assures a permanent union between them, We have previously shown that PHEMA sponges, within a certain range of pore size, can support cellular invasion and neovascularization when implanted into the rabbi t cornea, The present study is the first to evaluate the behavior of t he whole prosthesis after implantation into the rabbit cornea, METHODS : Hydrogel keratoprostheses were inserted intrastromally into the corn eas of seven rabbits and histologically examined by light microscopy i n five eyes enucleated at 8, 12, and 14 weeks. RESULTS: None of the im plants extruded over this period. Both clinical and histopathologic ex amination showed that the keratoprostheses were well tolerated by the host tissue. The porous skirt was fully integrated into the stroma by fibrovascular invasion, and no capsule formed around the implants. Str omal melting anterior to the implant occurred in two cases, but this d id not affect the fixation of the keratoprostheses, CONCLUSIONS: This study indicates that our keratoprosthesis can prevent extrusion in the short term when inserted into an intrastromal pocket of the rabbit ey e.