Differential efficacy of Conbercept vs. Ranibizumab on retinal microstructural changes in macular edema secondary to retinal vein occlusion during the loading phase.

OBJECTIVE: To compare the efficacy of Conbercept vs.Ranibizumab on retinal microstructural changes in patients with retinal vein occlusion-associated macular edema (RVO-ME) by evaluating multidimensional OCT biomarkers during the loading phase. METHODS: This retrospective cohort study analyzed treatment-naive RVO-ME patients receiving three monthly intravitreal injections of Conbercept or Ranibizumab. Propensity score matching (PSM) was used to balance baseline characteristics. Inter-group and intra-group comparisons of OCT biomarkers including central macular thickness (CMT), disorganization of the retinal inner layers ([DRIL), hyperreflective dots (HRD), intraretinal fluid (IRF), subretinal fluid (SRF), and ellipsoid zone (EZ) disruption] were performed using the Mann-Whitney U-test and the Friedman test. Generalized estimating equation (GEE) models were employed to evaluate longitudinal trends in CMT, DRIL, and IRF. RESULTS: After PSM, 108 patients (54 per group) were analyzed. Both agents showed significant improvements in all OCT biomarkers and BCVA at months 1 and 3 compared to baseline (all P < 0.05). Inter-group comparisons revealed that Ranibizumab achieved significantly lower CMT at months 1 (P = 0.011) and 3 (P = 0.006), and lower IRF at month 1 (P = 0.008). Conversely, Conbercept demonstrated significantly lower DRIL at month 3 (P = 0.004). GEE analysis confirmed a significant treatment-time interaction for DRIL (P = 0.004), indicating a more favorable longitudinal recovery of inner retinal microstructure with Conbercept, whereas no significant differences were observed in the longitudinal trends of CMT or IRF improvement (P > 0.05). CONCLUSIONS: Conbercept and Ranibizumab showed comparable primary outcomes and subtle divergences in exploratory secondary OCT biomarkers during the loading phase: Conbercept yielded greater DRIL reduction, whereas Ranibizumab achieved lower CMT and IRF at early time points. These preliminary findings may generate hypotheses for an OCT phenotype-driven approach to precision anti-VEGF therapy in RVO-ME.