Background/aims To evaluate the clinical outcome of a full-diameter, untrephined, semicircular Descemet graft in a consecutive series of Descemet membrane endothelial keratoplasty (hemi-DMEK), potentially allowing the harvesting of two grafts from a single donor corneoscleral rim.

Methods Interventional case series of 10 eyes of 10 patients with Fuchs endothelial dystrophy. Best corrected visual acuity (BCVA), endothelial cell density (ECD) and central corneal thickness (CCT) were evaluated up to 6 months postoperatively, and intraoperative and postoperative complications were recorded.

Results Hemi-DMEK was successful in 9 out of 10 eyes; one eye showed persistent graft detachment despite rebubbling and underwent a secondary DMEK. BCVA improved in all successful hemi-DMEK eyes: at 6 months 100% of eyes (n=7) reached ≥20/40 (≥0.5), 86% (n=6) ≥20/25 (≥0.8), 29% (n=2) ≥20/20 (≥1.0) and 14% (n=1) reached 20/17 (≥1.2). Two eyes were excluded from visual analysis due to low visual potential. Preoperative donor ECD declined from 2744 (±181) cells/mm² to 940 (±380) cells/mm² centrally at 6 months postoperatively (n=9), with (donor and/or host) endothelial cell redistribution over bare stromal areas adjacent to the graft. Average CCT decreased from 745 (±153) µm preoperatively to 520 (±37) µm at 6 months. Four eyes required rebubbling for visually significant graft detachment. No other complications occurred throughout the study period.

Conclusions Hemi-DMEK may give visual outcomes similar to those in conventional DMEK. If ECD decrease and graft detachment rate would prove acceptable in larger series, hemi-DMEK could have the potential to double the availability of donor tissue for endothelial keratoplasty.