Feasibility of cell-based therapy combined with descemetorhexis for treating Fuchs endothelial corneal dystrophy in rabbit model

Abstract

Corneal transparency is maintained by the corneal endothelium through its pump and barrier function. Severe corneal endothelial damage results in dysregulation of water flow and eventually causes corneal haziness and deterioration of visual function. In 2013, we initiated clinical research of cell-based therapy for treating corneal decompensation. In that study, we removed an 8-mm diameter section of damaged corneal endothelium without removing Descemet’s membrane (the basement membrane of the corneal endothelium) and then injected cultured human corneal endothelial cells (CECs) into the anterior chamber. However, Descemet’s membrane exhibits clinically abnormal structural features [i.e., multiple collagenous excrescences (guttae) and thickening] in patients with Fuchs endothelial corneal dystrophy (FECD) and the advanced cornea guttae adversely affects the quality of vision, even in patients without corneal edema. The turnover time of cornea guttae is also not certain. Therefore, we used a rabbit model to evaluate the feasibility of Descemet’s membrane removal in the optical zone only, by performing a small 4-mm diameter descemetorhexis prior to CEC injection. We showed that the corneal endothelium is regenerated both on the corneal stroma (the area of Descemet’s membrane removal) and on the intact peripheral Descemet’s membrane, based on the expression of function-related markers and the restoration of corneal transparency. Recovery of the corneal transparency and central corneal thickness was delayed in areas of Descemet’s membrane removal, but the cell density of the regenerated corneal endothelium and the thickness of the central corneal did not differ between the areas with and without residual Descemet’s membrane at 14 days after CEC injection. Here, we demonstrate that removal of a pathological Descemet’s membrane by a small descemetorhexis is a feasible procedure for use in combination with cell-based therapy. The current strategy might be beneficial for improving visual quality after CEC injection as a treatment for FECD.