Postoperative Endothelial Cell Density Is Associated with Late Endothelial Graft Failure after Descemet Stripping Automated Endothelial Keratoplasty.

PURPOSE: To determine whether preoperative endothelial cell density (ECD) and postoperative ECD after Descemet stripping automated endothelial keratoplasty (DSAEK) are associated with late endothelial graft failure (LEGF) in the Cornea Preservation Time Study (CPTS). DESIGN: Cohort study within a multicenter, randomized clinical trial. PARTICIPANTS: A total of 1007 individuals (1223 study eyes), mean age 70 years, undergoing DSAEK for Fuchs' dystrophy (94% of eyes) or pseudophakic or aphakic corneal edema (PACE) (6% of eyes) and followed for up to 5 years. METHODS: Central ECD was determined by a central image analysis reading center. Preoperative ECD was determined for 1209 eyes that did not fail and 14 eyes that experienced LEGF. The ECD at 6 and 12 months after DSAEK, the change in ECD from preoperative to 6 and 12 months, surgeon-reported operative complications, and postoperative graft dislocation were investigated for an association with LEGFs unrelated to other postoperative events. Univariable and multivariable Cox proportional hazards regression models were used to assess associations. MAIN OUTCOME MEASURES: Late endothelial graft failure and its associations with pre- and postoperative ECD and operative complications. RESULTS: The cumulative probability of LEGF was 1.3% (95% confidence interval [CI], 0.8%-2.4%). Median (interquartile range [IQR]) preoperative ECDs were similar for eyes with LEGF (2523; 2367-3161) cells/mm2) and eyes without failure (2727; 2508-2973) cells/mm2) (P = 0.34). The ECD at 6 months was associated with LEGF (P < 0.001) in time-to-event analyses, whereas preoperative ECD was not (P = 0.55). The cumulative incidence (95% CI) of LEGF was 6.5% (3.0%, 14.0%) for 97 grafts with a 6-month ECD less than 1200 cells/mm2, 0.3% (0.0%, 2.4%) for 310 grafts with a 6-month ECD between 1200 and 2000 cells/mm2, and 0.6% (0.1%, 2.7%) for 589 grafts with a 6-month ECD greater than 2000 cells/mm2. In multivariable analyses, ECD at 6 months and operative complications were both associated with LEGF (P = 0.002 and P = 0.01, respectively), whereas graft dislocation was not (P = 0.61). CONCLUSIONS: In eyes undergoing DSAEK, preoperative ECD is unrelated to LEGF, whereas lower ECD at 6 months is associated with LEGF. Early endothelial cell loss after DSAEK and intraoperative complications should be minimized to improve graft survival.

Effect of Graft Attachment Status and Intraocular Pressure on Descemet Stripping Automated Endothelial Keratoplasty Outcomes in the Cornea Preservation Time Study.

PURPOSE: To examine the association of donor, recipient, and operative factors on graft dislocation after Descemet stripping automated endothelial keratoplasty (DSAEK) in the Cornea Preservation Time Study (CPTS) as well as the effects of graft dislocation and elevated IOP on graft success and endothelial cell density (ECD) 3 years postoperatively. DESIGN: Cohort study within a multi-center, double-masked, randomized clinical trial. METHODS: 1090 individuals (1330 study eyes), median age 70 years, undergoing DSAEK for Fuchs endothelial corneal dystrophy (94% of eyes) or pseudophakic or aphakic corneal edema (6% of eyes). Recipient eyes receiving donor corneal tissue randomized by preservation time (PT) of 0-7 days (N = 675) or 8-14 days (N = 655) were monitored for early or late graft failure through 3 years. Donor, recipient, operative, and postoperative parameters were recorded including graft dislocation (GD), partial detachment, and pre- and post-operative IOP. Pre- and postoperative central donor ECD were determined by a central image analysis reading center. Proportional hazards, mixed effects, and logistic regression models estimated risk ratios and (99% confidence intervals). RESULTS: Three independent predictive factors for GD were identified: a history of donor diabetes (odds ratio [OR]: 2.29 [1.30, 4.02]), increased pre-lamellar dissection central corneal thickness (OR: 1.13 [1.01, 1.27] per 25µ increase), and operative complications (OR: 2.97 [1.24, 7.11]). Among 104 (8%) eyes with GD, 30 (28.9%) developed primary donor or early failure and 5 (4.8%) developed late failure vs. 15 (1.2%; P < .001) and 29 (2.4%; P = .04), respectively, of 1226 eyes without GD. 24 (2%) of 1330 study eyes had early acutely elevated postoperative IOP that was associated with a higher risk of graft failure through 3 years (hazard ratio: 3.42 [1.01, 11.53]), but not with a lower mean 3-year ECD (mean difference 61 (-479, 601) cells/mm2, P = .77). History of elevated postoperative IOP beyond 1 month was not significantly associated with 3-year graft success or ECD. CONCLUSIONS: Donor diabetes, increased donor corneal thickness, and intraoperative complications were associated with an increased risk of GD. Early acutely elevated postoperative IOP and GD significantly increased the risk for graft failure following DSAEK.