Intravitreal injection of Ranibizumab for the treatment of macular edema due to branch retinal vein occlusion

Objective To observe the clinical effects of intravitreal Ranibizumab injection (IVR) for the treatment of the macular edema due to branch retinal vein occlusion. Methods Sixty seven consecutive cases eyes of 67 of the macular edema due to branch retinal vein occlusion treated by IVR (10 mg/ml, 0.05 ml) were retrospectively analyzed. All the cases were divided by the following two methods. According to the time between oncome of the macular edema and the first therapy, the patients were divided into 3 groups: group 1 of less than 1 week, group 2 of 1week-3 months and group 3 of over 3 months. And according to the treating regulation, the patients were divided into 2 groups: treatment on time group and treatment on demand group. The follow-up contents included the best corrected visual acuity (BCVA, LogMAR), 1 mm diameter macular central retinal thickness (CRT) and fluorescence fundus angiography (FFA). The average follow-up period was (13.2±1.3) months. Results When the group division according to the time between oncome of the macular edema and the first therapy, the BCVA of the patients in group 1 was 0.131±0.061 and CRT was (268±21) μm two months after the treatment. The BCVA was 0.086±0.042 and CRT was (259±19)μm 12 months after the treatment. In group 2, the BCVA was 0.276±0.112 and CRT was (321±45) μm 2 months after the treatment and the BCVA was 0.292±0.105 and CRT was (268 ±29) μm 12 months after the treatment. In group 3, the BCVA was 0.523±0.164 and CRT was (441±67) μm two months after treatment, and the BCVA was 0.387±0.142 and CRT was (281±24) μm 12 months after the treatment. When compared with the group 1, at every follow-up time point, the differences in the BCVAs were statistically significant between group 1 and group 2 (all P<0.01). The CRTs at 2, 4, 6 months after the treatment between group 1 and group 3 had statistically significant differences (all P<0.01). When the group division according to the treatment regulation, 12 months after the treatment, the BCVA was 0.208±0.091 in the treatment on time group and was 0.387±0.184 in the treatment on demand group and the difference was statistically significant (t=4.35, P<0.01). Twelve months after the treatment, the CRT was (290±46) μm in the treatment on time group and was (311±51) μm in the treatment on demand group, and the difference was not statistically significant(t=0.98, P=0.56). Conclusion The curative effect of IVR for retinal edema due to branch retinal vein occlusion is obvious. Early and on time treatment could significantly improve the effects. Key words: Branch retinal vein occlusion; Edema, macular; Ranibizumab, intravitreal injection; Visual acuity