Early visual response provides additional prognostic value beyond baseline OCT features in diabetic macular edema

Purpose To compare baseline optical coherence tomography (OCT) characteristics and early visual response for predicting 12-month visual outcomes in eyes with diabetic macular edema (DME) treated with anti-vascular endothelial growth factor (anti-VEGF) therapy in a real-world setting. Methods This multicenter, retrospective, longitudinal study included 255 treatment-naïve patients (337 eyes) with DME who received intravitreal ranibizumab or aflibercept using a pro-re-nata regimen following three loading doses. Baseline OCT biomarkers and changes in best-corrected visual acuity (BCVA) at month 3 were evaluated as predictors of visual improvement at month 12. Generalized estimating equation (GEE) logistic regression models accounted for inter-eye correlation and model discrimination was assessed using receiver operating characteristic analysis. Results At month 3, 58.4% of eyes achieved at least a one-line improvement in BCVA. Early BCVA improvement was associated with visual gain at month 12 (odds ratio [OR] 5.78, 95% confidence interval [CI] 3.34–9.99, p < 0.001). Among baseline OCT parameters, preserved ellipsoid zone integrity (OR, 3.07; 95% CI, 1.09–8.64; p = 0.034) and absence of vitreomacular interface abnormalities (OR, 2.64; 95% CI, 1.02–6.84; p = 0.046) were associated with favorable outcomes. ROC analysis based on GEE-predicted probabilities showed higher discriminative ability for the early visual response model than for the baseline OCT model (AUC, 0.817; 95% CI, 0.768–0.865 vs. AUC, 0.766; 95% CI, 0.714–0.819; DeLong test, p = 0.037). Conclusion Baseline OCT features provide useful pretreatment prognostic information; however, early visual response after the loading phase offers additional dynamic prognostic insight. These findings suggest that final prognostic judgment should not rely solely on baseline OCT morphology and should be refined after the initial treatment response is assessed.