Risk Factors Predicting the Need for Graft Exchange after Descemet Stripping Automated Endothelial Keratoplasty

Purpose: To identify the risk factors predicting the need for graft exchange after Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: This is a retrospective cohort study. The study group included all 117 eyes that underwent or necessitated repeat DSAEK performed between January 2005 and June 2014 at Villa Serena-Villa Igea private hospitals (Forlì, Italy). The control group consisted of 1033 eyes that underwent only primary DSAEK during the same period. Demographic details, indications for primary surgery, ocular preoperative status and comorbidities, donor endothelial cell density (ECD), and postoperative complications were compared between the groups using univariate and multivariate analyses. Results: The prevalence of graft failure necessitating graft exchange was 10.2% (117 of 1150 eyes). In univariate analysis, a diagnosis of Fuchs endothelial dystrophy was a protective factor against the risk of repeat DSAEK. Prior trabeculectomy or aqueous shunt implantation, postoperative graft detachment, lower donor ECD, and a rejection episode were all associated with a significantly higher risk of requiring repeat DSAEK. The presence of buphthalmos, anterior chamber intraocular lens, aphakia, or prior penetrating keratoplasty were not risk factors for the failure of DSAEK. Of these variables, multivariate analysis showed that only prior aqueous shunt implantation [odds ratio (OR) 5.5, 95% confidence interval (CI), 1.4-22.2], lower donor ECD (OR 0.99, 95% CI, 0.997-0.999), and a documented postoperative rejection episode (OR 18.2, 95% CI, 7.9-45.0) predicted the need for repeat DSAEK. Conclusions: DSAEK grafts have similarly good long-term survival regardless of the indication for surgery, lens status, or ocular comorbidities, with the only exception being the presence of an aqueous shunt.