Association Between Postoperative Combined Antioxidant Supplementation and Corneal Endothelial Outcomes After Phacoemulsification

Objective: To evaluate the association between postoperative combined antioxidant supplementation and corneal endothelial outcomes following uncomplicated phacoemulsification cataract surgery. Methods: This retrospective observational cohort study included 112 patients who underwent uncomplicated phacoemulsification. Patients were divided into a supplementation group (n = 56) and a control group (n = 56) according to postoperative use of a combined oral antioxidant formulation. Corneal endothelial cell density, coefficient of variation, percentage of hexagonal cells, and central corneal thickness were assessed using non-contact specular microscopy preoperatively and at one and three months postoperatively. Longitudinal changes were evaluated using linear mixed-effects models. Results: Baseline characteristics were comparable between groups. At postoperative month one, central corneal thickness was lower in the supplementation group than in controls (p = 0.026), whereas this difference was no longer significant at month three. Linear mixed-effects analysis demonstrated a significant group × time interaction only for central corneal thickness. Endothelial cell density was numerically higher in the supplementation group at postoperative months one and three, but neither intergroup comparisons nor mixed-effects analysis showed statistically significant group-related differences. Coefficient of variation and hexagonality also did not show significant group-related differences over time. No supplement-related adverse events were documented. Conclusion: Postoperative combined antioxidant supplementation was associated with a transient difference in early postoperative central corneal thickness, while no significant group-related differences were demonstrated for endothelial cell density or morphology. These findings should be regarded as exploratory and do not establish a biological mechanism or causal protective effect.