Graft preparation for hemi-Descemet membrane endothelial keratoplasty (hemi-DMEK)

There is a substantial shortage of donor tissue for endothelial keratoplasty worldwide. Using two endothelial grafts of one donor cornea may potentially increase the pool of suitable donor tissue for Descemet membrane endothelial keratoplasty (DMEK). This study evaluates the technical feasibility of obtaining two DMEK grafts with a different (semicircular) shape, but similar surface area as a 'conventional' 8-9 mm circular transplant from a single donor cornea and to evaluate the viability of these grafts stored in organ-culture medium up to 5 weeks after graft preparation.

Ten human corneas not suitable for transplantation were used for preparation of semicircular-shaped grafts (hemi-DMEK grafts). The viability of these hemi-DMEK grafts was measured by evaluating the endothelial cell density (ECD) with light microscopy before and immediately after preparation and during five additional weeks of organ culture.

Hemi-DMEK preparation was successful in all cases. All grafts formed a roll. A small area denuded of cells was observed after preparation along the straight edge of the DM roll. The mean ECD was 2654 (±65) cells/mm(2) before and 2651 (±94) cells/mm(2) immediately after hemi-DMEK preparation and declined gradually from 2518 (±133) cells/mm(2) after 1 week to 1847 (±170) cells/mm(2) after 5 weeks of organ-culture storage.

Preparation of two hemi-DMEK grafts from one single human donor cornea is technically feasible, and the grafts can be stored after preparation in organ-culture similar to standard circular DMEK grafts. Hemi-DMEK may have the potential to double the availability of donor endothelial tissue for DMEK.