Risk Factors for Graft Rejection Following Endothelial Keratoplasty: Focus on Cystoid Macular Edema

Purpose: The aim of this study was to investigate risk factors of immunologic graft rejection following endothelial keratoplasty, with a focus on cystoid macular edema (CMO). Methods: This is a single-center retrospective case review study including eyes undergoing either Descemet membrane endothelial keratoplasty (DMEK) or Descemet stripping automated keratoplasty (DSAEK). Univariate and multivariate analyses were conducted to evaluate whether several predetermined risk factors could influence the incidence of graft rejection. Receiver operating characteristic curve analysis was performed to determine ideal cutoff points of continuous variables. The following risk factors were assessed: recipient age, sex, indication for surgery, type of keratoplasty, glaucoma, and development of CMO. Results: A total of 3546 eyes were included, with 731 undergoing DMEK and 2815 undergoing DSAEK. The mean follow-up duration was 49.5 ± 37.9 months (median = 36 months). The incidence of graft rejection was 2.9% for DMEK and 4.0% for DSAEK ( P = 0.150) and was significantly influenced by the patients’ age (odds ratio OR = 2.17, 95% confidence interval CI, 1.46–3.24), the presence of glaucoma (OR = 2.28, 95% CI, 1.50–3.46), and postoperative occurrence of CMO (OR = 11.09, 95% CI, 6.58–18.70) (all P < 0.001). The mean interval between the onset of CMO and the occurrence of rejection was 11.5 ± 14.1 months, with a median of 6 months. Conclusions: Occurrence of CMO, as well as the presence of glaucoma and a recipient's age <71.5 years, seems to play a significant role in the development of endothelial graft rejection following endothelial keratoplasty. Further studies are indicated to investigate a possible immunologic link between CMO and endothelial graft rejection episodes.