Histological Study of Newly Designed Keratoprosthesis in Rabbits

Abstract

Abstract: : Purpose: We reported our newly designed kertoprosthesis (K-pro) in ARVO 2002. In this study, we evaluated the histological changes of the wound edge between the host cornea and our K-pro. Methods: Our K-pro consists of 3 components: optics part, porous skirt and guard part. Optics part and guard part are one piece structure of PMMA. The diameter of optic part and total K-pro are 3.5mm and 6.0mm, respectively. Donut shaped porous skirt (made of polyurethane, 0.4mm in thickness and 1.0mm in width) is glued surrounding optics part. We implanted our K-pros to rabbit corneas. After 2, 4, 8, 12, and 24 weeks, the rabbits were sacrificed and the corneas were obtained for histological study. After fixation with 4% paraformaldehyde, they were embedded in resin followed by thin sectioned and stained by toluidine blue. Then, we evaluate the histological changes of wound edge between host cornea and the K-pro in time course. Results: Porous skirt and host cornea were attached well without any gap in between up to 24 weeks after surgery. The invasion of keratocytes into porous skirt and the infiltration of inflammatory cells at wound edge of host cornea were observed at 2 weeks. The number of invaded keratocytes and the amount of synthesized collagen tissue in the porous skirt increased gradually up to 12 weeks. The infiltration of inflammatory cells at wound edge almost disappeared at 8 weeks. Corneal epithelium spread partially on the surface of porous skirt from 8 weeks. Conclusions: It was demonstrated that our K-pro showed good bio-compatibility with invaded keratocytes and synthesized collagen tissue. Coverage of the skirt surface by corneal epithelium should be obtained in the future.

Keywords: keratoprostheses • transplantation