Efficacy of Hyperbaric Oxygen Therapy in Diabetic Retinopathy and Macular Edema: A Systematic Review and Meta-Analysis

Background: Diabetic retinopathy (DR) and diabetic macular edema (DME) are major causes of vision loss in diabetes. Hyperbaric oxygen therapy (HBOT) has been explored as an adjunctive treatment due to its potential to enhance oxygenation, reduce inflammation, and lower oxidative stress in retinal tissues. This systematic review and meta-analysis assessed HBOT’s efficacy in improving best-corrected visual acuity (BCVA) and central macular thickness (CMT). Methods: A comprehensive search across major databases up to May 2025 identified five eligible studies involving 463 eyes. Results: Pooled data showed HBOT significantly improved BCVA (mean difference—0.05 LogMAR; 95% CI: −0.09 to −0.01; p < 0.05) with no heterogeneity (I² = 0%), suggesting consistent functional benefit. However, sensitivity analysis revealed this effect was fragile, losing significance when the largest study was excluded. For CMT, HBOT was associated with a significant reduction (−75.21 (95% CI −90.04 to −60.38; p < 0.05), though heterogeneity was high (I² = 62%), likely due to differences in patient profiles and treatment combinations.