Abstract
Purpose :
To determine if the presence of Descemet membrane (DM) impacts endothelial cell migration and phenotype in-vivo.
Methods :
In group 1, New Zealand white rabbits underwent endothelial removal by scraping (7mm) (n=5). In group 2 underwent 7mm descemetorhexis (n=5). In group 3, descemetorhexis was followed by implantation of an over-lapping, decellularized, human Descemet membrane graft; Descemet membrane transplantation (DMT)(n=5). Animals were followed up at days 1,3,5,8,11,14,21 and 28 with slitlamp and OCT examination. Trypan blue dye was injected into the anterior chamber and the size of the residual wound was measured at each time point until full wound closure was observed for group 1 & 2. Animals were sacrificed and the corneal endothelium examined using scanning electron microscopy, immunofluorescence and histology.
Results :
Central corneal thickness was higher in group 2 at all time points and failed to return to normal by 28 days . Corneal thickness (CCT) returned to normal (<400µm) by day 8 in group 1(p<0.01). Trypan blue assessment of wounds showed full closure by day 5 in group 1 vs 14 days in group 2. Corneas in group 1 recovered normal clarity. In group 2 wound closure was associated with the development of a fibrous scar. Healed wounds in group 1 contained endothelial cells with normal tight junctions that expressed Na+/K+ ATPase, and had a healthy mosaic pattern. Endothelial cells in group 2 became fibroblastic, exhibited prominent stress fibers were a-SMA positive, suggestive of endothelial to mesenchymal transformation. Performing a descemetorhexis followed by DMT resulted in reversion to the scrape phenotype observed for group 1, with no significant difference in CCT at any time point between groups 1 and 3 and healthy endothelial cells observed on the transplanted acellular DM (fig. 1).
Conclusions :
The data presented here suggests endothelial cells migrate faster in-vivo when the DM is preserved. Preservation of DM also promotes the maintenance of a normal endothelial phenotype. Interest in regenerative medicine approach’s to treating Fuchs endothelial dystrophy (FED) is growing. Results from primary descemetorhexis in humans are mixed. Since preservation of native DM is not possible in FED as guttae affect vision and cell migration, performing Descemetorhexis followed by a new procedure we have termed DMT may be preferable to stripping alone.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.