Early dynamic response on spectral-domain OCT predicts long-term visual outcome in diabetic macular edema treated with aflibercept

OBJECTIVE: A retrospective evaluation of the long-term visual recovery prediction in patients with diabetic macular edema (DME) following aflibercept treatment, based on spectral-domain optical coherence tomography (SD-OCT) parameters at one and four months post-treatment. METHODS: This study involved 112 eyes of 112 DME patients which received at least one injection of aflibercept. SD-OCT parameters at 1 and 4 months post-aflibercept treatment-including central subfield thickness (CST), the continuity of external limiting membrane (ELM)/ellipsoid zone (EZ) and cone outer segment tip (COST), as well as the counts of retinal hyperreflective retinal foci (HRF), along with best-corrected visual acuity (BCVA) improvement at 12 months post-treatment-were analyzed. The correlation between SD-OCT parameters and BCVA improvement was evaluated using the chi-square or Wilcoxon test, and the predicted value of SD-OCT parameters was assessed via receiver operating characteristic (ROC) curve and binary logistic regression model. RESULTS: Twelve months after aflibercept treatment, BCVA was improved from 0.66 ± 0.46 to 0.48 ± 0.42 logMAR (p = 0.002). The SD-OCT parameters were significantly improved: CST was decreased from 397.05 ± 199.60 to 289.08 ± 119.39 μm; the affected eyes with damaged ELM/EZ and COST decreased from 46 (41.1%) and 71 (63.4%) to 31 (27.7%) and 43 (38.4%), respectively; the number of HRF decreased from 11.00 ± 11.38 to 8.03 ± 9.58. The AUC values for predicting BCVA gain of ≥ 5 letters at 12 months based on SD-OCT parameters at 1 and 4 months post-aflibercept treatment and their combination were 0.812, 0.824, and 0.873, respectively. Multivariate logistic analysis revealed that CST, ELM/EZ, COST, and HRF at 1 and 4 months were all independent predictors of long-term visual improvement outcomes. CONCLUSION: Intravitreal injection of aflibercept can effectively improve the vision and fundus structure of DME patients. Improvements in short- and medium-term CST, ELM/EZ, COST integrity, and HRF values are key physiological indicators for visual recovery.