Analysis On The Clinical Effect And Visual Acuity Prognostic Factors Of BRVO-ME Treated With Ranibizumab

Objective:Evaluate the functional and structural changes of foveal macula after intravitreal ranibizumab injection in patients with macular edema secondary to branch retinal vein occlusion(BRVO-ME)by optical coherence tomography angiography(OCTA)and multifocal electroretinography(mf ERG)and screen the factors that can predict the final visual acuity of the patients.Methods:Prospective,clinical study.In this prospective single-arm study,we observed 26 patients(26 eyes)diagnosed with BRVO-ME who were enrolled from 2018.09-2019.10 in the first central hospital of Baoding.All patients received monthly ranibizumab 0.5 mg injections for 3 consecutive months.The central macular thickness(CMT)and best-corrected visual acuity(BCVA)were measured before and 1 mo after the every time injection.The vessel perfusion density(VPD),vessel length density(VLD)and fovea avascular zone(FAZ)of superficial capillary plexus(SCP)were evaluated with OCTA before and after treatment.Mf-ERG was used to analyze the amplitude density of P1 wave and latency of P1,N1 wave from ring 1 and ring 2.SPSS 19.0 statistical software was used for data analysis.Results:1.Fundus observation:Fundus photographs showed that the retinal hemorrhage of BRVO-ME obsorbed significantly than before treatment.2.Best Corrected Visual Acuity(BCVA): BCVA(Log MAR)was 0.773±0.304 before treatment,and BCVA(Log MAR)was 0.323±0.086 after 3 months of intravitreal injection of ranibizumab,significantly higher than before treatment(t=6.778,P < 0.05).3.CMT: CMT was 489.346±137.453 before treatment,and after 3 months of intravitreal injection of ranibizumab were 239.385±33.175.Compared with that before treatment,CMT decreased significantly(t=9.053,P < 0.05).4.The vessel density and FAZ of SCP: The vessel perfusion density,vessel length density and FAZ of SCP before treatment were(13.073±2.858),(0.320±0.083),(0.315±0.118)and after treatment,they were(14.069±2.796),(0.376±0.130)and(0.358±0.135),respectively.There was no significant change and no significant difference(t=-1.421,-1.985,-1.518,P > 0.05).5.mf-ERG amplitude density and latency of P1,N1 wave:After 3 months of intravitreal injection of ranibizumab,the latency of P1,N1 wave from ring 1 and ring 2 were significantly lower than those before treatment,while the amplitude density value of P1 wave was increased compared with that before treatment,with statistically significant differences(P <0.05).6.Factors related to vision prognosis:Pearson correlation analysis showed that there was a correlation between age,preoperative BCVA,VLD,VPD,FAZ and visual acuity improvement(P < 0.05).There was a negative correlation between age,FAZ and visual acuity improvement,and a positive correlation between BCVA,VLD,VPD and visual acuity improvement.Conclusion:1.Intravitreal injection of ranibizumab once a month for three consecutive months to treat BRVO-ME can significantly improve the electrophysiological activity of the macular area,stabilize the blood flow state of the macular area,but no obvious improvement in the microcirculation structure of the macular area.2.Age,preoperative BCVA,VPD,VLD and FAZ can be used as predictors of vision improvement.