Intravitreal Versus Subtenon Triamcinolone Acetonide Injection for Diabetic Macular Edema: A Systematic Review and Meta-analysis

Objective: To compare the efficacy of intravitreal (IV) triamcinolone acetonide (IVTA) versus subtenon (ST) triamcinolone acetonide (STTA) injection for the treatment of diabetic macular edema (DME). Methods: Searches for randomized clinical trials published between 1 January 1950 and 15 March 2011 were conducted using PubMed, MEDLINE, EMBASE, and the Cochrane Library included in the present meta-analysis are five randomized controlled trials, each with a minimum follow-up of 3 mo. All included studies evaluated the efficacy of TA for the treatment of refractory DME, and compared IVTA with STTA by measuring visual acuity (VA), central macular thickness (CMT), and intraocular pressure (IOP). Results: One mo post-injection, treatment with IVTA had significantly improved VA (MD, -0.14 logMAR; 95% CI = -0.16 to -0.13) and reduced CMT (MD = -174.02 mu m; 95% CI = -249.97 to -98.08) compared with STTA. At 3 mo post-injection, treatment with IVTA had significantly improved VA (MD = -0.07 logMAR; 95% CI = -0.09 to -0.05) and reduced CMT (MD = -119.46 mu m; 95% CI = -176.55 to -62.36) compared with STTA. The benefits of either treatment were no longer significant at 6 mo, and patients had to be retreated. Compared with STTA, IVTA injections produced no difference in IOPs at 1 mo, higher IOPs at 3 mo, and lower IOP values at 6 months Conclusions: Within 3 mo, IVTA is more effective than is STTA in improving VA and reducing CMT in patients with refractory DME. However, the benefits of either regimen were no longer evident at 6 mo.