Bevacizumab for macular edema secondary to retinal vein occlusion: a systematic review and meta-analysis

To assess the effect and safety of using single intravitreal bevacizumab (IVB) versus intravitreal triamcinolone acetonide (IVTA) and grid laser photocoagulation (GLP), or a combination of IVB and IVTA for treatment of retinal vein occlusion (RVO)-associated macular edema, mainly exploring its effects on visual acuity (VA) and central macular thickness (CMT).

Eligible studies were identified via searching databases, including Medline (PubMed), Web of Science, and the Cochrane Library, without status or other limits up to June 2012.

We include randomized clinical control trials comparing 1.25 mg IVB injection with other treatment strategies, including a 4 mg IVTA injection or GLP or a combination of 1.25 mg IVB and 2 mg IVTA injection, for patients with RVO-associated macular edema. Eligible studies should report both VA and CMT outcomes, and with a minimum follow-up of 4 weeks. Results: Two authors assessed the trial quality and extracted data independently.

Four studies were included in this study. Comparing to IVTA and GLP, IVB was more effective in improving VA at 1 month (weighted mean difference [WMD], -0.07; 95% confidence interval [CI], -0.10 to -0.05; P<0.00001), 3 months (WMD, -0.24; 95% CI, -0.28 to -0.20; P<0.00001), and 6 months during the follow-up (WMD, -0.17; 95% CI, -0.21 to -0.13; P<0.00001) in patients with RVO-associated macular edema. There was no statistical significance in reducing CMT values throughout the periods. Compared with IVB/IVTA combination, VA improvement became statistically significant at 3 months of follow-up (WMD, -0.26; 95% CI, -0.29 to -0.23; P<0.00001), while no statistical significance was found in both VA values at 1 month of follow-up and CMT values throughout the periods. The occurrence of intraocular pressure (IOP) was much lower in IVB groups.

IVB is effective in treating patients with RVO-associated macular edema; especially if it has distinct effects, of which, VA could be improved to the utmost extent as well as by the earliest of time. IVB is also effective in decreasing CMT, but without any significant advantages over IVTA or GLP. Furthermore, IVB seems to be safer than IVTA in consideration of IOP increase.