Serum Vitamin D Levels as Predictors of Response to Intravitreal Anti-VEGF Therapy in Diabetic Macular Edema: A Clinical Correlation Study

Our study explored the role of serum 25-hydroxyvitamin D [25(OH)D] levels as a indicator of response to intravitreal anti-VEGF therapy in patients with diabetic macu-lar edema (DME), highlighting functional and anatomical outcomes linked to systemic biomarker profiles. In a cohort of treatment-naive diabetic patients, vitamin D status was correlated with post-treatment changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA), illustrating layered therapeutic responses among deficient, insufficient, and sufficient vitamin D groups. Functional gains, measured as improvements in decimal BCVA, and anatomical improvements, defined by CMT re-duction via SD-OCT, were primarly detected in patients with sufficient vitamin D lev-els. Remarkably, patients with serum 25(OH)D ≥30 ng/mL revealed complete du-al-response rates, while those in the deficient group manifested partial therapeutic ef-ficacy, supporting the immunoangiogenic modulatory role of vitamin D. Statistical as-sociations exposed a tight linear connection between baseline and final visual acuity and a pronounced inverse relationship between CMT and final vision, suggesting that vitamin D may play a rhole in treatment-mediated structural recovery. These results may imply that low vitamin D levels lead to subclinical endothelial dysfunction and impaired retinal barrier repair, possibly through dysregulated VEGF signaling, chronic inflammation, and oxidative stress. Our findings underscore the need and importance of further research of vitamin D status as an adjunctive biomarker in the clinical ap-proach of personalized DME and validates the potential of circulating vitamin D evalu-ation in therapeutic classification and predictive eye care.