Descemet Endothelial Thickness Comparison Trial: A Randomized Trial Comparing Ultrathin Descemet Stripping Automated Endothelial Keratoplasty with Descemet Membrane Endothelial Keratoplasty

Purpose: To compare clinical outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) in the treatment of corneal endothelial dysfunction. Design: Patient and outcome-masked, randomized controlled clinical trial. Participants: Patients with damaged or diseased endothelium from Fuchs endothelial dystrophy or pseudophakic bullous keratopathy who were considered good candidates for DMEK or UT-DSAEK. Methods: Study eyes were randomized by the eye bank to UT-DSAEK or DMEK 1 to 2 days before surgery. Main Outcome Measures: The primary outcome of the trial was best spectacle-corrected visual acuity (BSCVA) at 6 months. Secondary outcomes included 3- and 12-month BSCVA; 3-, 6-, and 12-month endothelial cell counts; intraoperative and postoperative complications; and change in pachymetry. Results: A total of 216 patients with endothelial dysfunction were screened, and 50 eyes of 38 patients were enrolled by 2 surgeons at Casey Eye Institute at Oregon Health & Science University in Portland, Oregon, and at Byers Eye Institute at Stanford University in Palo Alto, California. Overall, we found DMEK to have better visual acuity outcomes compared with UT-DSAEK after correcting for baseline visual acuity: compared with UT-DSAEK, those randomized to DMEK had 1.5 lines better BSCVA at 3 months (95% confidence interval [CI], 2.5–0.6 lines better; P = 0.002), 1.8 lines better BSCVA at 6 months (95% CI, 2.8–1.0 lines better; P < 0.001), and 1.4 lines better BSCVA at 12 months (95% CI, 2.2–0.7 lines better; P < 0.001). Average endothelial cell counts were 1963 cells/mm² in DMEK and 2113 cells/mm² in UT-DSAEK at 6 months (P = 0.17) and 1855 cells/mm² in DMEK and 2070 cells/mm² in UT-DSAEK at 12 months (P = 0.051). Intraoperative and postoperative complication rates were similar between groups. Conclusions: Descemet membrane endothelial keratoplasty had superior visual acuity results compared with UT-DSAEK at 3, 6, and 12 months in patients with isolated endothelial dysfunction with similar complication rates.