[Experiences in animal experiments with hydrogel keratoprosthesis of different water content]

Satisfactory results could be obtained in former animal experiments with keratoprostheses made by 38% hydrated hydrogel plastics (PHEMA). There still existed some doubts concerning alterations by aging of this material, possibly resulting in setting free toxic or allergenic substances as well as raising the risk of infection. Therefore, keratoprostheses containing 38 or 20% water were implanted in rabbit eyes. The follow-up period of 44 animals was 6 months. No essential differences in the postoperative course of both types of keratoprostheses could be observed. With the only exception of a growth of tissue over the optical cylinder in 1 case no serious complications, e.g., extrusion of the implant, occurred. Regarding the greater resistibility of the less hydrated hydrogel, this more durable plastic seems to be the more adapted material for keratoprotheses.