Abstract:AIM: To compare the effects of intravitreal injection of bevacizumab (IVB) with intravitreal triamcinolone acetonide (IVTA) on the treatment of cystoid macular edema (CME) secondary to retinal vein occlusion (RVO). METHODS: A literature search was conducted using PubMed, the Cochrane Central Register of Controlled Trials, Web of Science and the Chinese Biomedical Database. The comparison was divided into two groups, group 1 conducted comparison in branch RVO (BRVO) or central RVO (CRVO), group 2 conducted comparison in ischemic-RVO or nonischemic-RVO. Pooled mean differences (MDs) for changes in visual acuity (VA), central macular thickness (CMT) and intraocular pressure (IOP) were calculated in groups at 4, 12 and 24wk after treatment respectively. RESULTS: Eight studies comparing the efficacy of IVB with IVTA were included in the Meta-analysis. In group 1, in BRVO, significant difference was shown on the comparison of CMT at 24wk (MD, -45.66; 95% CI, -76.03 to -15.28; P=0.003), IVB was effective on BRVO for at least 24wk; no significant differences were found in the comparison of VA at each time points (P>0.05 respectively). In CRVO, no significant differences were found in the comparison of VA or CMT between IVB and IVTA at each time points (P>0.05, respectively). In group 2, in ischemic-RVO, significant differences were shown in the comparison of VA (MD, -0.28; 95% CI, -0.42 to -0.14; P<0.0001) and CMT (MD, -86.50; 95% CI, -151.18 to -22.43; P=0.008) at 24wk; In nonischemic-RVO, no significant differences were demonstrated in the comparison of VA or CMT between IVB and IVTA at each time points (P>0.05, respectively). The occurrence of high IOP was much lower in IVB group. CONCLUSION: This Meta-analysis suggested that IVB was effective in decreasing CMT in BRVO for at least 24wk, IVB is more effective on improving VA and reducing CMT in ischemic-RVO. IVB is more promising on RVO than IVTA.