Flushing Versus Pushing Technique for Graft Implantation in Descemet Membrane Endothelial Keratoplasty

PURPOSE Descemet membrane endothelial keratoplasty (DMEK) has developed into a safe procedure for the replacement of diseased corneal endothelium. However, DMEK still results in a significant donor endothelial cell loss. Here, we compare 2 different graft implantation techniques. METHODS Twenty patients undergoing DMEK, where a DMEK injection cartridge was used to flush the graft into the anterior chamber (G-38635 single-use DMEK-Cartridge; Geuder AG, Heidelberg, Germany; group A), were retrospectively compared with 20 patients, where a standard lens injection cartridge (AT.Smart Cartridge; Carl Zeiss Meditec AG, Jena, Germany; group B) was used to push the graft with a plunger. Outcome parameters were intraoperative orientation of the graft, insertion-to-attachment time, rebubbling rates, and postoperative best spectacle-corrected visual acuity, endothelial cell count, and central corneal thickness after 12 months. The surfaces of both cartridges were evaluated by scanning electron microscopy. RESULTS In group A, the insertion-to-attachment time was significantly higher (P = 0.003). Initially, the graft was oriented correctly in 40% of the patients in group A compared with 90% in group B (P = 0.001). No differences were obtained between both groups regarding central corneal thickness, endothelial cell count or best spectacle-corrected visual acuity, and rebubbling rates after 12 months. Scanning electron microscopy analysis demonstrated a rougher and sharper surface of the shooter of group B. CONCLUSIONS This study shows significant differences between both insertion techniques regarding correct graft orientation directly after graft implantation leading to prolonged insertion-to-attachment time when the graft is flushed instead of pushed into the anterior chamber.