Clinical Outcome of Endothelium-Outward Preloaded Descemet Membrane Endothelial Keratoplasty in Long-Term Dextran-Containing Transport Medium Preservation

Purpose: To analyze the clinical outcome of organ-cultured endothelium-outward preloaded DMEK (pDMEK) using the RAPID cartridge. Methods: This prospective study included 80 eyes of 80 patients who received a pDMEK. Best-corrected visual acuity (BCVA), endothelial cell count (ECC), and central corneal thickness were measured preoperatively and 4 to 6 weeks, 3 months, 6 months, and 1 year postoperatively. The difficulty of graft preparation and implantation, rebubbling, and re-DMEK frequency were evaluated. Results: The graft preparation time was 5.3 ± 1.2 minutes on average. After preparation, the ECC before preloading was 2652 ± 180 cells/mm 2 ( P = 0.9, endothelial cell loss [ECL] = 0.8%). After pDMEK, the cornea started to clear up after 1.6 ± 1 day. Compared with the preoperative values, BCVA and central corneal thickness significantly improved during the postoperative course ( P < 0.0001). At the first follow-up examination, the ECL was 43% ( P < 0.0001) and remained stable throughout the follow-up period (all P > 0.5). Rebubbling was necessary in 39/80 patients (48.75%). One patient (1/80, 1.25%) required a re-DMEK after 1 year owing to secondary graft failure with insufficient ECC. Conclusions: The clinical results after endothelium-outward pDMEK showed a significant improvement in BCVA and corneal thickness over the 1-year follow-up period, but the relatively high rebubbling rate and ECL should be taken into account. Therefore, we recommend that further comparative clinical studies should be conducted.