Endothelial Keratoplasty: The Relationship between Donor Tissue Storage Time and Donor Endothelial Survival

Abstract

To evaluate the relationship between storage time in Optisol GS (Bausch & Lomb, St. Louis, MO) and postoperative cell loss after Descemet's stripping automated endothelial keratoplasty (DSAEK) surgery. Retrospective analysis of a noncomparative, interventional case series. Three hundred sixty-two eyes of 265 patients undergoing DSAEK surgery for Fuchs' endothelial dystrophy. Storage times (death to surgery) of donor tissue were recorded for 362 eyes undergoing DSAEK surgery. Donor cell loss at 6, 12, and 24 months was recorded. Analysis of storage times with endothelial cell loss was performed using a Pearson correlation coefficient and an independent samples Student t test. Percentage of donor endothelial cell loss as measured by specular microscopy of central endothelial cell density (ECD). The mean storage time was 98.95 ± 33 hours (range, 20.65-186.02 hours). The mean percent endothelial cell loss from before to after surgery was 29 ± 16% at 6 months (n = 362), 31 ± 16% at 12 months (n = 263), and 32 ± 20% at 24 months (n = 98). Storage time did not correlate significantly with endothelial cell loss at any postoperative time point (6 months: r = -0.047, P = 0.373; 12 months: r = -0.023, P = 0.709; 24 months: r = -0.14, P = 0.169). The mean cell loss for corneas stored 0 to 4 days (n = 55) was 32 ± 17% at 2 years and the mean cell loss for corneas stored for more than 4 days (n = 43) was 30 ± 18% at 2 years (P = 0.57). At the extremes of storage time, 10 corneas stored for the shortest time (1.5 days) had a 1-year cell loss of 33% and 10 corneas stored for the longest time (7 days) had a 1-year cell loss of 30% (P = 0.45). No correlation was found between the characteristic of storage time and the decline of ECD. Surgeons should not make special requests to the eye bank for short storage times with the hope of improving donor endothelial survival. The upper limit of donor storage time as it relates to acceptable postoperative endothelial cell loss is not known.