[Histological study of the effect of conjunctival transplantation on rabbit cornea with alkali burned]

A histopathological study to investigate the efficacy of conjunctival auto-transplantation on alkaline chemical burns of the ocular surface.

An alkaline chemical burn model was developed in one eye of rabbits using 0.1 N NaOH solution. In one group conjunctival transplantation was performed. A control group did not receive conjunctival transplantation. A histological follow-up study was performed by light microscopy with hematoxylin eosin stain and periodic acid Schiff staining by fluoro-microscopy using epithelial Keratin-AE 5 antibody, and by transmission electron microscopy(TEM).

The transplanted group showed scar formation between the transplanted conjunctival tissue and the sclera. At 20 days and 8 weeks after the transplantation, neovascularization and cell infiltration in the subepithelium of the limbus was decreased compared with the transplanted group at 10 days. The control group showed a decrease of cell infiltration in the limbal area compared with the group at 10 days, but conjunctival tissue with thick collagenous tissue and neovascularization instead of scar tissue developed on the injured cornea. AE 5 positive cells were not found in the limbus in either group. In the transplanted group, in TEM, the basement membrane of transplanted conjunctiva showed less irregularity, and degenerated fibroblasts were present at the margin of the scar tissue. In the control group, the basement membrane of the conjunctiva showed an irregular pattern and fibroblasts beneath the conjunctival epithelium had large nuclei.

In the transplanted group, scar tissue developed and suppressed cell infiltration, neovascularization, and conjunctival tissue in the injured cornea and secured re-structuring of the limbal tissue.