Abstract
Purpose :
To investigate mid-term remodeling of corneal endothelial cells (CECs) in and outside the graft area post Descemet`s membrane endothelial keratoplasty (DMEK) and compare the regional and individual difference of endothelial change by non-contact and slit-scanning wide-field contact specular microscopy.
Methods :
This study involved 7 eyes of 7 patients [Fuchs’ corneal dystrophy: n=4; pseudo phakic bullous keratopathy (BK): n=1; posterior polymorphous corneal dystrophy: n=1; laser iridotomy-induced bullous keratopathy: n=1; mean patient age: 61.3±12.6 years] treated by DMEK using internationally shipped donor corneas. Mean follow-up time was 45 months and minimum follow-up time was 36 months. A slit-scanning wide-field contact specular microscopy (Konan Medical, Inc.) and a non-contact specular microscope (SP-3000; TOMEY Corp.) were used to analyze CEC remodeling in and outside the graft area post DMEK.
Results :
Mean endothelial cell density (ECD) in the graft center pre DMEK was 2870±225 cells/mm2, yet decreased 45.6% to 1631±315 cells/mm2 at 1-year postoperative and 72.5% to 1333±388 cells/mm2 at 3-years postoperative. Wide-field specular microscopy revealed endothelial migration and filling of the denuded stroma outside the graft. ECD gradation from the center to periphery was notable at 3-months post DMEK, and the gradient slope appeared flat following continuous endothelium loss. The yearly mean ECD reduction rate was -6.5±17.5% at 2-years and -12.1±11.1% at 3-years. The ECD gradient from the center to the paracentral region of the graft ranged 20-39%, matching the ECD in the center (814-2114 cells/mm2) at 3-years postoperative. However, no significant ECD reduction was observed at the area of bare sclera outside the graft and the graft edge connected to the host endothelium.
Conclusions :
Endothelial remodeling produced a cell density gradient and variations of endothelial distribution following the cell migrations and cell loss post DMEK, even in the mid-term postoperative period. Continuous loss of CECs led to a flat distribution of ECD from the graft center to the edge, however, high ECD was retained and maintained the steep distribution of ECD, thus suggesting that the loss of the endothelium at the graft edge post DMEK notably influences the mid-term survival of CECs.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.