Long-term outcomes after Descemet membrane endothelial keratoplasty: cumulative transplant burden and visual outcomes.

Abstract

Objective: To evaluate long-term outcomes after Descemet membrane endothelial keratoplasty (DMEK), focusing on cumulative transplant burden, time-to-event outcomes, and visual acuity (VA).

Design: A retrospective cohort study.

Participants: A total of 320 eyes from 246 patients undergoing DMEK with ≥5 years of follow-up (with 25% of patients having ≥10 years of follow-up).

Methods: Clinical data were reviewed to assess graft failure, repeat corneal transplantation, cumulative transplant burden, VA, and endothelial cell density (ECD). Kaplan-Meier and Cox proportional hazards models were used for time-dependent outcomes. Multivariable logistic regression identified predictors of VA.

Results: Sixty-six eyes (20.6%) required ≥1 additional corneal transplant. Eyes with bullous keratopathy (BK) had a greater transplant burden than Fuchs endothelial dystrophy (p < .001). Kaplan-Meier analysis showed reduced graft failure-free and transplant-free survival in BK eyes (both p < .001). In Cox models, BK was independently associated with graft failure (hazard ratio [HR] 4.67; p = .001) and repeat transplantation (HR 3.41; p = .019). VA improved from 0.82 to 0.44 logMAR at 1 year (p < .001), with favourable observed outcomes at longer follow-up. Greater transplant burden was associated with worse final VA (p < .001); however, only the 2-transplant category reached statistical significance after adjustment (adjusted odds ratio 2.35; p = .045). ECD declined predictably over time, with greater loss in BK eyes (p = .001).

Conclusions: DMEK provides substantial long-term visual improvement; however, outcomes extend beyond graft survival. Eyes with BK and ocular complexity have higher transplant burden and risk of failure. Increasing transplant burden is associated with worse visual outcomes, highlighting the importance of individualized long-term management and counseling.