Abstract
Abstract: :
Purpose:To evaluate the efficacy of autograft and allograft of the reconstructed corneal layer composed of epithelium and keratocyte on the lyophilized amniotic membrane (AM) in severely alkali–burned cornea model. Methods:After biopsy specimens were obtained from the left eyes of 7 rabbits, the corneal epithelial cells and keratocyte were expanded in vitro. To reconstruct the corneal layer composed of epithelium and keratocyte, the keratocyte was first cultivated on the stromal side of AM for 5 days, followed by the epithelial culture on the other side using air–lift method. 35 eyes of rabbits underwent alkali burn (1N NaOH, 30 sec) to create limbal deficiency with damaged corneal stroma. Three days later, the rabbits were distributed into five experimental groups. Group 1 was transplanted with autograft, group 2 underwent allograft with cyclosporine, group 3 underwent allograft without cyclosporine, group 4 underwent only lyophilized AM, and group 5 was served as control without surgery. Corneal vascularization and opacity were photo–documented at postoperative 30, 60, 90, and 180 days. Corneas were prepared for hematoxylin–eosin staining, immunostaining for K3/K12 and collagen IV and also the transmission electron microscope. Results:Wound healing and stabilization of ocular surface in groups 1 and 2 were much faster than those of group 3, 4 and 5. Group 4 and 5 revealed typical limbal deficiency with conjunctivalization and persistent epithelial defect. The cornea in groups 1 and 2 showed a nearly normal clear cornea, with a mild peripheral neovascularization. In group 1 and 2, K3/K12 and collagen IV were strongly expressed in the cornea epithelium and basement membrane, respectively. The basement membrane in these groups was well established between recovered corneal epithelium and AM, and overlying epithelium on AM revealed multilayered differentiation. Conclusions:Transplantation of the reconstructed corneal layer composed of epithelium and keratocyte on lyophilized AM might be therapeutically useful in the treatment of patient with severely damaged cornea.
Keywords: cornea: clinical science • wound healing • transplantation