Predictive factors of long-term visual outcomes after primary Descemet's membrane endothelial keratoplasty (DMEK): retrospective study.

Purpose: To determine predictive factors of higher levels of best-corrected visual acuity (BCVA) in the long-term after primary Descemet's membrane endothelial keratoplasty (DMEK).

Methods: Retrospective, single-surgeon case series of 129 successful primary DMEK eyes without graft failure and with a minimum postoperative follow-up of 12 months. Mixed effect model for repeated measurements (MMRM) analysis was performed to determine recipient, donor, surgical and postoperative factors associated with BCVA ≤ 0.10 logMAR (≥ 20/25 Snellen).

Results: After primary DMEK, there was a statistically significant improvement in BCVA with a global reduction in logMAR BCVA (p < 0.00001). There was also a global tendency towards increasing proportion of eyes with BCVA ≤ 0.10 logMAR at all time points (p < 0.00001), from 1.6% before DMEK to 64.4% in eyes with more than 5 years of F-U. Absence of retinal disease was associated with a decrease of 0.10 logMAR in postoperative BCVA after primary DMEK, maintaining constant the rest of variables (p < 0.001). The variables age (OR 0.960), postoperative time (OR 1.083), preoperative BCVA ≥ 0.375 logMAR (OR 0.162) and indication for DMEK (OR 5.412) were included in the predictive MMRM model of BCVA ≤ 0.10 logMAR.

Conclusion: Primary DMEK is associated with statistically and clinically significant improvement in BCVA that occur early in the postoperative period and are continuous over time. Eyes with retinal comorbidities have increased risk of worse postoperative BCVA after DMEK. Younger recipient age, Fuchs' dystrophy eyes and eyes with better preoperative BCVA are more likely to achieve postoperative BCVA ≤ 0.10 logMAR.