Relationship between tissue unscrolling time and endothelial cell loss

Abstract

Purpose: To assess the relationship between intraoperative unscrolling time of the donor Descemet membrane endothelial keratoplasty (DMEK) tissue and 6-month postoperative endothelial cell loss (ECL), and to determine whether donor age, scroll tightness, and the presence of an S stamp are related to unscrolling time. Methods: Ninety-three consecutive uncomplicated DMEK surgeries performed on eyes with Fuchs endothelial dystrophy using our standardized technique (ie, prestripped tissue with or without a premarked S stamp from our eye bank, overstripping the recipient, Straiko glass injector, no-touch tap technique, and bubble of 20% SF6 gas) were evaluated. Intraoperative unscrolling times and 6-month endothelial cell densities were measured and analyzed. Results: Sixty-nine cases comprised the study cohort. The median unscrolling time was 4 minutes (range: 0.8-17.5 minutes), and the median ECL was 26.9% (range: 24.3% to 80.0%). There was no relationship between unscrolling time and ECL at 6 months by the Pearson correlation coefficient (r = 20.02, P = 0.89). Younger donor age, tighter scrolls, and absence of an S stamp had no correlation with longer unscrolling times (all P. 0.05). Only 2 of 4 cases of iatrogenic primary graft failure had unscrolling times available for analysis; in this limited sample, there was no association between iatrogenic primary graft failure and unscrolling time. Conclusions: Once the DMEK tissue is safely in the anterior chamber, surgeons need not rush the "DMEK dance" because longer unscrolling times may not endanger the endothelium.