Efficacy of intravitreal conbercept injection on short-and long-term macular edema in branch retinal vein occlusion

AIM: To observe the best-corrected visual acuity(BCVA) and central foveal thickness(CFT) repeatedly after the intravitreal injection of conbercept(IVC) for treating cystoid macular edema(CME) in branch retinal vein occlusion(BRVO) and explore the relationship between the duration of CME and visual outcome.METHODS: Subgroup analysis was performed to compare short-term(within 90 d of CME onset) and longterm(over 90 d of CME onset) macular edema in BRVO.After an initial IVC, a pro re nata(PRN) strategy was performed according to the recurrence of CFT or decrease of BCVA.Analysis of variance using repeated measurements, statistical analysis following indicators including BCVA and CFT collected at baseline and 1, 3, and 6 mo after IVC.RESULTS: Among the 60 cases included in this retrospective study, 36 were short-term CME, and 24 were long-term CME.There were statistical significances between and within groups of the BCVAs at different time points(P<0.001).The interaction was found between group and time(P=0.006), indicating the difference in the speed of BCVA improvement between groups.In particular, the improvement speed of BCVA in the short-term CME group was faster than that in the long-term CME group.There were significant differences between and with groups of the CFT at different time points(P<0.001).However, the interaction between group and time in relation to CFT had no significant differences(P=0.59).CONCLUSION: IVC treatment for CME following BRVO is effective and safe.The duration of CME before treatment is a significant predictor of the visual outcomes of patients with BRVO.The improvement of vision might be faster with early IVC treatment than with delayed treatment.