Descemet Membrane Endothelial Keratoplasty versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty: A Multicenter Randomized Controlled Clinical Trial

Purpose: To compare best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), refractive astigmatism, and complications after Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK).

Design: Prospective, multicenter randomized controlled trial.

Participants: Fifty-four pseudophakic eyes of 54 patients with corneal endothelial dysfunction resulting from Fuchs endothelial corneal dystrophy were enrolled in 6 corneal centers in The Netherlands.

Methods: Participants were allocated to DMEK (n = 29) or UT-DSAEK (n = 25) using minimization randomization based on preoperative BSCVA, recipient central corneal thickness, gender, age, and institution. Donor corneas were prestripped and precut for DMEK and UT-DSAEK, respectively. Six corneal surgeons participated in this study.

Main outcome measures: The primary outcome measure was BSCVA at 12 months after surgery.

Results: Central graft thickness of UT-DSAEK lamellae measured 101 μm (95% confidence interval [CI], 90-112 μm). Best spectacle-corrected visual acuity did not differ significantly between DMEK and UT-DSAEK groups at 3 months (0.15 logarithm of the minimum angle of resolution [logMAR] [95% CI 0.08-0.22 logMAR] vs. 0.22 logMAR [95% CI 0.16-0.27 logMAR]; P = 0.15), 6 months (0.11 logMAR [95% CI 0.05-0.17 logMAR] vs. 0.16 logMAR [95% CI 0.12-0.21 logMAR]; P = 0.20), and 12 months (0.08 logMAR [95% CI 0.03-0.14 logMAR] vs. 0.15 logMAR [95% CI 0.10-0.19 logMAR]; P = 0.06). Twelve months after surgery, the percentage of eyes reaching 20/25 Snellen BSCVA was higher in DMEK compared with UT-DSAEK (66% vs. 33%; P = 0.02). Endothelial cell density did not differ significantly 12 months after DMEK and UT-DSAEK (1870 cells/mm² [95% CI 1670-2069 cells/mm²] vs. 1612 cells/mm² [95% CI 1326-1898 cells/mm²]; P = 0.12). Both techniques induced a mild hyperopic shift (12 months: +0.22 diopter [D; 95% CI -0.23 to 0.68 D] for DMEK vs. +0.58 D [95% CI 0.13-1.03 D] for UT-DSAEK; P = 0.34).

Conclusions: Descemet membrane endothelial keratoplasty and UT-DSAEK did not differ significantly in mean BSCVA, but the percentage of eyes achieving 20/25 Snellen vision was significantly higher with DMEK. Endothelial cell loss did not differ significantly between the treatment groups, and both techniques induced a minimal hyperopic shift.