Factors Affecting the Success Rate of Preloaded Descemet Membrane Endothelial Keratoplasty With Endothelium-Inward Technique: A Multicenter Clinical Study

center dot PURPOSE: To evaluate factors affecting the outcomes of preloaded Descemet membrane endothelial keratoplasty (pl-DMEK) with endothelium-inward. center dot DESIGN: Retrospective clinical case series and a com-parative tissue preparation study. center dot METHODS: Participants : Fifty-five donor tissues for ex vivo study and 147 eyes of 147 patients indicated with Fuchs en-dothelial dystrophy or pseudophakic bullous keratopathy with or without cataract. Intervention : Standardized DMEK peeling was performed with 9.5-mm-diameter trephination followed by second trephination for loading the graft (8.0-9.5 mm diameter). The tissues were manually preloaded with endothelium -inward and preserved for 4 days or shipped for trans-plantation. Live and dead assay and immunostaining was performed on ex vivo tissues. For the clinical study, the tissues were delivered using bimanual pull-through tech-nique followed by air tamponade at all the centers. Main outcome measures : Tissue characteristics, donor and recipient factors, rebubbling rate, endothelial cell loss (ECL), and corrected distance visual acuity (CDVA) at 3, 6, and 12 months. center dot RESULTS: At day 4, significant cell loss ( P = .04) was observed in pl-DMEK with loss of biomarker expression seen in prestripped and pl-DMEK tissues. Rebubbling was observed in 40.24% cases. Average ECL at 3, 6, and 12 months was 45.87%, 40.98%, and 47.54%, respec-tively. CDVA improved significantly at 3 months post -operation (0.23 +/- 0.37 logMAR) ( P < .01) compared to the baseline (0.79 +/- 0.61 logMAR). A significant as-sociation ( P < .05) between graft diameter, preservation time, recipient gender, gender mismatch, and recipient age to rebubbling rate was observed. center dot CONCLUSION: Graft loading to delivery time of pl-DMEK tissues in endothelium-inward fashion must be limited to 4 days after processing. Rebubbling rate and overall surgical outcomes following preloaded DMEK can be multifactorial and center-specific. (Am J Ophthal-mol 2022;241: 272-281. (c) 2022 Elsevier Inc. All rights reserved.)Superscript/Subscript Available