Systematic review of intravitreal bevacizumab injection for treatment of primary diabetic macular oedema

Purpose: To compare intravitreal bevacizumab (IVB) injection versus macular photocoagulation (MPC) or a combination of intravitreal bevacizumab and intravitreal triamcinolone acetonide (IVB/IVTA) injection in improving visual acuity (VA) of patients with primary diabetic macular oedema (DMO). Methods: The following databases were searched: Medline (1950 - December week 3, 2009), The Cochrane Library (Issue 4, 2009), EMBASE (up to 24 December 2009), and the TRIP database (up to 23 December 2009), using no language or other limits. Randomized controlled trials were included that consisted of patients with primary DMO (not with refractory DMO), those comparing IVB injection with MPC or IVB/IVTA injection, those reporting VA outcomes, and those having a minimum follow-up of 6 weeks. Results: In the four randomized clinical trials comparing IVB injection with MPC, IVB injection demonstrated significantly greater improvement in VA at 6 weeks, but not at 12 weeks. In the three randomized clinical trials comparing IVB injection with IVB/IVTA, IVB injection demonstrated greater improvement in VA at 6 weeks but the benefit was again no longer significant at 12 weeks. No adjunctive effect of IVTA was demonstrated. Conclusions: Intravitreal bevacizumab injection is effective in improving VA in patients with primary DMO for 6 weeks, but the benefits are no longer present 12 weeks following the injection.