Risk Factors and Effect of Sub-Tenon Triamcinolone on Cystoid Macular Edema After Descemet Membrane Endothelial Keratoplasty: Association and Risk Factor Analysis

Purpose: To evaluate whether sub-Tenon triamcinolone acetonide (STTA) reduces cystoid macular edema (CME) after Descemet membrane endothelial keratoplasty (DMEK) and to identify associated risk factors. Methods: This retrospective, multicenter observational study included 96 eyes of 78 patients who underwent DMEK in Japan and were followed for ≥12 months. Demographic, ocular, and surgical variables were collected. CME was assessed using spectral-domain optical coherence tomography. Kaplan–Meier analysis with log-rank testing compared CME-free survival between eyes with and without STTA. Cox proportional hazards regression identified risk factors. Best-corrected visual acuity at 12 months was compared between CME-positive and CME-negative eyes. Results: CME developed in 13 eyes (13.5%). Kaplan–Meier analysis showed no significant difference in CME-free survival between STTA users (90.9%) and nonusers (84.6%) at 360 days ( P = 0.593). Most CME cases occurred within 90 days postoperatively. Multivariable analysis indicated that preoperative anterior chamber depth showed a trend toward association with CME ( P = 0.058), and rebubbling was independently associated with increased risk ( P = 0.034). Eyes requiring ≥2 rebubbling procedures had a higher CME risk compared with eyes without rebubbling ( P = 0.029). Age, STTA use, and nonsteroidal antiinflammatory drug use were not significantly associated with CME. At 12 months, best-corrected visual acuity did not differ between groups ( P = 0.419). Conclusions: STTA was not significantly associated with a lower incidence of CME after DMEK. Shallow anterior chamber depth showed a trend toward association, and rebubbling was significantly associated, suggesting the need for careful postoperative evaluation.