Descemet Membrane Endothelial Keratoplasty after failed penetrating keratoplasty- case series and review of the literature

Abstract

Background This study aims to evaluate visual outcome, central corneal thickness, and re-bubbling rate in a cohort with undersized sequential Descemet Membrane Endothelial Keratoplasty (DMEK) due to endothelial graft decompensation following primary penetrating keratoplasty (PK). Methods All patients who received a sequential DMEK (n=16) or triple DMEK (n=2) after failed primary PK between November 2020 and June 2022 were retrospectively evaluated. Analyzed parameters were corrected distance visual acuity (CDVA), central corneal thickness (CCT), re-bubbling rate and graft survival. Results 18 eyes of 18 patients were included. All patients underwent a DMEK with undersized graft after failed PK(s). Mean time between the last PK and DMEK was 102±82 weeks. Mean follow-up time was 8.9±4.6 months. CDVA increased significantly from 1.12±0.60 logMAR preoperatively to 0.64±0.49 logMAR 6 weeks postoperatively (p=0.013). Mean CCT decreased significantly from 807±224 μm before to 573±151 μm 6 weeks after DMEK (p=0.003). Re-bubbling was necessary in eight eyes (44.4%) after a median time of 7 days. The 12-month Kaplan Meier survival was 66.7%. Conclusion In case of endothelial graft decompensation without stromal scars after primary PK, a DMEK can be performed for selected patients who had satisfying CDVA before the endothelial decompensation. Prior to DMEK indication, an AS-OCT should routinely be performed to circularly search for posterior steps at the PK graft margin, as well as shortly after DMEK to exclude a detachment of the endothelial graft. All patients should be informed about a higher re-bubbling rate in comparison to primary DMEK.