IMPLANTATION OF PHEMA KERATOPROSTHESES AFTER ALKALI BURNS IN RABBIT EYES

Purpose. We have previously examined histologically the healing of a P HEMA core-and-skirt keratoprosthesis (the Chirila KPro) as a full-thic kness implant in healthy animal corneas. The present study was carried out to determine whether a diseased cornea could also generate biocol onization of the skirt region of a KPro. Methods. Ten KPros were place d as full-thickness corneal implants under conjunctival flaps in 10 al kali-burned rabbit corneas. Histological findings at intervals from 2 weeks to 6 months postoperatively were compared with earlier findings in 10 rabbits that had received identical KPros without prior alkali i njury. Results. Despite severe corneal injury and the reduced keratocy te population present, there were no clinically detected complications in 60%. Histological findings established that, compared with healthy host tissue, skirt biocolonization and KPro-cornea healing after an a lkali burn were impaired, with evidence of epithelial downgrowth in 40 %. One animal required euthanasia earlier than the planned end point, but no KPro extrusions occurred. Conclusion. Biocolonization of a KPro skirt is reduced but not prevented in an alkali-induced corneal infla mmation model. Although no extrusions occurred, close follow-up and an ticollagenolytic medication would be required to minimize the complica tion rate.