Evolution of Consecutive Descemet Membrane Endothelial Keratoplasty Outcomes Throughout a 5-Year Period Performed by Two Experienced Surgeons

Abstract

Purpose: To assess the evolution of clinical outcomes of more than 1300 Descemet membrane endothelial keratoplasties (DMEKs) alone or in combination with cataract surgery (triple DMEK) throughout a 5-year period at a single center, performed by 2 already experienced DMEK surgeons.

Design: Retrospective trend study.

Methods: Review of charts between July 2011 and July 2016 at the Department of Ophthalmology, University of Cologne, Germany.

Results: A total of 1340 out of 1340 eyes with sufficient information were included. Six-month and 12-month best spectacle-corrected visual acuity (logMAR) had already reached high levels for the surgeries performed in 2011 (0.10 ± 0.06 and 0.09 ± 0.07, respectively) and did not further improve in later years (P = .272). Likewise, endothelial cell loss (ECL) and central corneal thickness (CCT) reached comparable levels independently of the year of surgery (average 12-month ECL was 38% ± 15% and average 6-month CCT decrease was 19% ± 11%). However, there was a decrease in the rebubbling rate, from 68% in 2011, 67% in 2012, and 70% in 2013 to 53% in 2014, 29% in 2015, and 16% in 2016, which was associated with the introduction of 20% sulfur hexafluoride (SF₆) instead of room air for anterior chamber tamponade in 2015 (n = 986; P < .001). The percentage of severe complications after DMEK surgery also decreased significantly with surgeons' growing experience (P < .001; 95% confidence interval [0.09; 0.12]) over the years.

Conclusions: After an initial learning curve in DMEK surgery, results of visual acuity and ECL do not seem to further improve. However, the complication rate continuously declines, at least over the subsequent 5-year period analyzed herein.