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

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. 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. 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). 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.