Allograft Transplantation of Functional Epithelial Corneal Cell Layers in Rabbits

Abstract

Abstract: : Purpose: The development of corneal tissue constructs for the treatment of ocular surface disease is still evolving. The purpose of this study was to demonstrate the usefulness of heterologous cultivated limbal epithelial cell grafts for ocular surface reconstruction. Methods: Limbal stem cell deficiency was induced in 5 New Zealand White rabbits by anterior lamellar keratectomy including the limbal area. Previously, a small 2.5 mm² limbal sample was obtained from healthy eyes of randomly selected male rabbits. Limbal epithelial cells were cultivated, and 21 days later epithelial sheets were ready to be grafted. The epithelial grafts were sutured covering the exposed corneal stroma. The control group included 5 rabbits that underwent surface keratectomy without grafting. The animals received topical tobramicine and dexametasone during 2 weeks after surgery. Clinical follow up was performed up to 90 days. Rabbits were euthanized at day 2, 7, 30 and 90 and the corneas processed for histopathologic examination. Results: Clinically, the corneas were clear in all grafted animals. A full thickness continuous layer of stratified epithelial cells was seen in grafted corneas. Control animals showed a thinner regenerative epithelium and more pronounced fibroblastic proliferation. Neither clinical nor histological evidence of immune reaction was observed. Conclusions: Allografts of bioengineered full thickness limbal epithelium were able to differentiate in corneal epithelium and remain intact up to 3 months without significant immune reactions. Heterologous corneal epithelial cell transplantation may be a promising procedure for bilateral ocular surface disease.

Keywords: cornea: stroma and keratocytes • anterior segment • transplantation