DMEK outcome after one year - Results from a large multicenter study in Germany

Area of Science:

• Ophthalmology
• Corneal Surgery
• Transplantation Medicine

Background:

• Descemet membrane endothelial keratoplasty (DMEK) is a prevalent corneal transplant procedure in Germany, accounting for over 50% of all corneal transplants.
• Large-scale multicenter data on DMEK outcomes have been limited.

Purpose of the Study:

• To evaluate the outcomes of a large cohort of Descemet membrane endothelial keratoplasty (DMEK) procedures performed across multiple centers.
• To assess visual acuity, endothelial cell density, corneal thickness, and complication rates associated with DMEK.

Main Methods:

• A retrospective analysis of 3200 DMEK procedures for Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK) at seven departments.
• Evaluation of best corrected visual acuity (BCVA), endothelial cell density (ECD), corneal thickness (CT), and rates of rebubbling, primary transplant failure, and immune reactions.
• Statistical analysis using linear mixed models for repeated measures and weighted linear regression to assess changes over time and correlation with center volume.

Main Results:

• For patients without vision-limiting comorbidities, mean BCVA improved significantly from 0.6 logMAR preoperatively to 0.1 logMAR at 12 months postoperatively (p < 0.001).
• Bullous keratopathy (BK) patients had worse BCVA compared to Fuchs endothelial corneal dystrophy (FECD) patients at 1 year (0.3 vs. 0.1 logMAR, p < 0.001).
• Endothelial cell density declined from 2465 cells/mm² preoperatively to 1587 cells/mm² at 12 months (p < 0.001).
• The overall graft failure rate was 3% and the rejection rate was 1.5%.
• A rebubbling rate of 0.4/eye was observed, with 25% of eyes requiring at least one rebubbling. More rebubblings correlated with lower ECD, worse BCVA, higher CT, and increased transplant failure and rejection rates (p < 0.001).
• A single rebubbling did not significantly influence BCVA (p = 0.785).

Conclusions:

• Descemet membrane endothelial keratoplasty (DMEK) effectively enhances visual acuity with low rates of graft failure and immune rejection.
• Fuchs endothelial corneal dystrophy (FECD) demonstrates a better visual outcome compared to bullous keratopathy (BK).
• The need for rebubbling in approximately 25% of cases should be discussed during informed consent, although one rebubbling does not negatively impact the final visual outcome.