Purpose: To present the functional and anatomic changes after intravitreal bevacizumab in eyes with macular edema (ME) due to branch retinal vein occlusion (BRVO).
Design: The study was a retrospective study.
Materials and methods: The study included 31 patients with ME due to BRVO. We compared the examination findings of patients with ME before and after intravitreal bevacizumab therapy at 12 months. The study included patients who had macular edema secondary to BRVO treated with bevacizumab. The therapy was started in the first week after occlusion. The initial therapy was three intravitreal bevacizumab injections at monthly intervals with 1.25/0.05 mL bevacizumab. Patients with a baseline visual acuity less than 0.5 (logarithm of the minimum angle of resolution [logMAR] 0.30), central macular thickness (CMT) more than 290 μm, and no neovascularization were included. Patients with diabetes mellitus or a history of intravitreal triamcinolone or grid laser photocoagulation therapy or ischemic BRVO were excluded. The retreatment criteria were as follows: increased CMT more than 100 μm combined with a loss of visual acuity of five or more letters. The statistical analysis of this study was carried out by paired samples t-test (SPSS). A P value of less than 0.05 was considered to be statistically significant.
Results: This retrospective study included 33 eyes of 31 patients (20 women, 11 men; mean age was 55.30 ± 9.62 years (range 36-75 years). Patients received a mean of 5.3 injections during 12 months of follow-up. The best corrected visual acuity increased from 0.66 ± 0.20 (logMAR) at baseline to 0.22 ± 0.13 (logMAR) (t = 15.42; P < 0.001) at month 12. The CMT decreased from 494.15 ± 104.16 μm at baseline to 261.79 ± 45.36 μm at month 12 (- 232.36 ± 109.98 μm); P < 0.001). No bevacizumab-related systemic or ocular adverse effects following intravitreal drug injections were observed. The majority of patients required reinjection(s) treatment for ME (84.9%).
Conclusion: Intravitreal therapy using bevacizumab appears to be an effective primary treatment option for ME due to BRVO. No serious ophthalmologic or systemic side effects were observed for intravitreal bevacizumab therapy. The main disadvantage of bevacizumab therapy is the requirement of multiple injections in order to maintain visual and anatomic improvements.
Keywords: branch retinal vein occlusion; central macular thickness; intravitreal bevacizumab injection; macular edema; visual acuity.