Multicenter Study of 6-Month Clinical Outcomes After Descemet Membrane Endothelial Keratoplasty

Purpose: To report the 6-month clinical outcomes of a large cohort of Descemet membrane endothelial keratoplasty (DMEK) eyes operated by 55 starting or experienced surgeons. Methods: This is a retrospective, multicenter, interventional, cohort study with a total of 2485 eyes. Best-corrected visual acuity (BCVA), endothelial cell density (ECD) decrease, and intra-and post-operative complications were evaluated. Three groups based on case order were compared: group I (cases 1-24), group II (cases 25-99), and group III (cases >= 100). Forty-nine percent of the surgeons were in their learning curve (< 25 cases), representing 10.4% of the surgeries. Results: Six months after DMEK, BCVA improved in 90.5% of eyes, remained unchanged in 4.6%, and deteriorated in 4.9% (n = 1936); 75.4% of eyes reached a BCVA of >= 20/40 (>= 0.5), 45.4% >= 20/25 (>= 0.8), and 25.8% >= 20/20 (>= 1.0) (n = 1959) and ECD decreased by 40% (+/- 19) (n = 1272, P < 0.05). BCVA and ECD outcomes did not differ between groups I and III (P > 0.05). Intraoperative complications were reported for 9.4% of eyes, whereas graft detachment was the main postoperative complication (27.4%), with lower intra-and post-operative complication rates in group III than group I (P < 0.05). Rebubbling was performed in 20.1% of eyes; 13.8% required secondary keratoplasty within 6 months. Conclusions: DMEK is applicable for surgeons in various settings with good clinical outcomes. After an arbitrary learning curve (<25 cases), virtually all transplant-related complications declined with experience. Notably, surgeons with a higher annual caseload may pass faster through their learning curve than surgeons performing their first surgeries over an extended period.