Intravitreal versus Sub-Tenon Posterior Triamcinolone Injection in Bilateral Diffuse Diabetic Macular Edema

<i>Purpose:</i> To compare the efficacy of intravitreal and sub-Tenon (ST) posterior triamcinolone injection in the treatment of bilateral diabetic diffuse macular edema (DDME). <i>Methods:</i> 28 eyes of 14 diabetic patients with bilateral DDME were included in this prospective randomized study. One eye of each individual received a sub-Tenon (ST) posterior triamcinolone injection (ST group), whereas the fellow eye received an intravitreal triamcinolone injection (IV group). All eyes were treated with supplementary focal laser after the injections. Cases were evaluated 1, 2, 3 and 6 months after the initial treatment. <i>Results:</i> Both groups had visual improvement and macular edema reduction following the injections. This temporary effect was prominent for 24 weeks in the IV group and for 8 weeks in the ST group. Edema resorption and visual improvement were more pronounced in the IV group, although this difference was not statistically significant. No major complications were observed except for moderate and reversible intraocular pressure elevation in some cases. <i>Conclusion:</i> Both intravitreal and ST injections of triamcinolone appear to yield a significant visual recovery and prompt resolution of DDME. The beneficial outcome appears to be more longstanding with intravitreal injection.