Evaluation of Spectral Domain OCT Changes Following Anti-VEGF Therapy in Diabetic Macular Edema

Background: Diabetic macular edema (DME) is a leading cause of visual impairment in diabetic retinopathy. Spectral-domain optical coherence tomography (SD-OCT) enables high-resolution assessment of retinal microstructural changes. Antivascular endothelial growth factor (anti-VEGF) therapy is the standard treatment for DME; however, anatomical and functional outcomes vary. This study evaluates SD-OCT morphological changes following anti-VEGF therapy and their correlation with visual outcomes. Materials and Methods: A prospective observational study was conducted on 100 eyes of 92 DME patients at a tertiary care center. All patients received three monthly intravitreal injections of bevacizumab (1.25 mg/0.05 ml). Baseline and post-treatment evaluations included best-corrected visual acuity (BCVA) and SD-OCT imaging. OCT biomarkers such as central macular thickness (CMT), cystoid macular edema (CME), subretinal fluid (SRF), disorganization of retinal inner layers (DRIL), ellipsoid zone (EZ) disruption, external limiting membrane (ELM) status, and hyperreflective foci (HRF) were assessed. Results: Post-treatment analysis showed significant reduction in CMT and resolution of CME and SRF in many cases. Partial restoration of EZ and ELM, as well as decreased HRF and DRIL, were associated with improved BCVA. Central-involving DME and EZ disruption were significantly associated with poorer outcomes. Conclusion: Anti-VEGF therapy leads to measurable anatomical improvements on SD-OCT in DME. Specific OCT biomarkers can aid in predicting visual response and guiding management.