Prestained and Preloaded DMEK Grafts: An Evaluation of Tissue Quality and Stain Retention

Purpose: To examine endothelial cell damage and stain retention of prestained preloaded Descemet membrane endothelial keratoplasty (DMEK) grafts. Methods: DMEK grafts were stained with trypan blue or left unstained before loading into a Straiko modified Jones tube. A protocol to stain preloaded grafts inside the modified Jones tube and resulting cell loss was also examined. Endothelial cell loss was determined by vital dye staining after 3 days of cold storage and compared between the 3 groups. Eight additional grafts were stained, loaded, and shipped from Oregon to New York to assess stain stability. Stain retention and the ability to successfully inject and open these “prestained preloaded” grafts in cadaveric donor eyes were also evaluated. Results: Unstained preloaded DMEK grafts showed an overall cell loss of 15% ± 3% [95% confidence interval (CI), 11%–18%]. Prestained grafts had a cell loss of 16% ± 4% (95% CI, 10%–22%) and were not significantly different from unstained grafts (P = 1). Grafts stained while inside the modified Jones tubes had an average cell loss of 18% ± 2% (95% CI, 16%–20%, Pprestained = 0.15, Punstained = 0.09). All grafts shipped across the country and examined 3 days after preparation showed a decrease in stain intensity but were still deemed suitable for transplantation by an experienced DMEK surgeon. Conclusions: It is possible to prestain and preload DMEK grafts without inducing additional endothelial cell loss. Consideration should be given to the interval between staining and surgery because stain can fade.