Intravitreal bevacizumab with or without triamcinolone acetonide for diabetic macular edema: a meta-analysis of randomized controlled trials

Background Intravitreal anti-vascular endothelial growth factor (anti-VEGF) drugs and corticosteroids are being widely used to treat diabetic macular edema (DME). The purpose of this study was to evaluate further the efficacy and safety of intravitreal bevacizumab (IVB) alone in comparison with intravitreal bevacizumab combined with triamcinolone acetonide (IVB/IVT) in the treatment of DME. Methods Pertinent publications were identified through CNKI, PubMed, Medline, EMBASE, and the Cochrane Controlled Trials Register up to November 30, 2013. Two investigators independently assessed the quality of the trials, and changes in central macular thickness (CMT) and best-corrected visual acuity (BCVA) were extracted at 6 weeks and 3, 6, 12, and 24 months after the initial treatment. A meta-analysis was carried out to compare the results between the groups receiving IVB and IVB/IVT using the software RevMan 5.0. Results A total of six randomized controlled trials (RCTs) were identified and included. The meta-analysis revealed that a significant reduction of the CMT was observed at 3 months after the initial treatment in the IVB/IVT group compared to the IVB group (P=0.001). Also, changes in CMT at 6 weeks and 6, 12, and 24 months did not vary significantly between the IVB and IVB/IVT groups (P=0.53, 0.76, 0.34, and 0.09, respectively). Similarly, changes in BCVA at 6 weeks and 3, 6, 12, and 24 months also did not vary significantly between the two groups (P=0.66, 0.98, 0.81, 0.07, and 0.80, respectively). The results were robust to sensitivity analyses. However, the rate of intraocular pressure (IOP) rise after intravitreal injections varied significantly between the IVB and IVB/IVT groups (P <0.01). A publication bias was not detected by funnel plots, the Egger method, or the Begg method. Conclusions Results of this meta-analysis showed that the treatments with IVB alone and combined IVB/IVT were similarly effective in improving the visual acuity, and, to some degree; combined IVB/IVT appeared to offer a marginal advantage over IVB in decreasing CMT in patients with DME. However, the addition of IVT resulted in intraocular pressure rise in some treated patients.