Allogeneic Descemet's Membrane Transplantation Enhances Corneal Endothelial Monolayer Formation and Restores Functional Integrity Following Descemet's Stripping.

Abstract

To characterize the differences in corneal endothelial wound healing in the presence or absence of Descemet's membrane (DM), in vivo. New-Zealand white rabbits were subjected to 7-mm endothelial wound either by scraping (n = 8; DM intact), peeling (n = 6; DM removed), or a combinatory scrape/peel wound (n = 6). In a second experiment, rabbits underwent peel wound with immediate transplantation of pure decellularized human DM (n = 4). In vivo endothelial migration was assessed via trypan blue staining. Recovery of corneal clarity and thickness was performed by using slit-lamp biomicroscopy and optical coherence tomography. Cell proliferation, phenotype, and morphology were assessed by using immunofluorescence and scanning electron microscopy. In vivo wound closure was faster in the presence of DM; 25.4% ± 1.4%/d versus 5.5% ± 0.6%/d (P < 0.0001). At day 8, complete wound closure was seen in all of the scrape samples but none of the peel group, with wound closure preceding clinical recovery by approximately 6 days in the scrape group. Endothelial cells in the scraped areas reformed functional monolayers capable of restoring corneal thickness and transparency whilst those in the peeled area underwent mesenchymal-like transformation resulting in scar formation. Transplanting decellularized DM in animals receiving a peel wound resulted in clarity and thickness comparable to the scrape group. Endothelial proliferation (Ki67 +ve cells) was higher in scraped versus peeled areas: 54.7% ± 3.5% vs. 8.8% ± 0.7%, (P < 0.01). The presence of DM promoted endothelial wound healing, proliferation, and maintenance of a normal phenotype. DM transplantation recovered the abnormal peel phenotype back to that observed after endothelial scraping.