Intravitreal versus Posterior Subtenon Injection of Triamcinolone Acetonide for Diabetic Macular Edema

PURPOSE To compare the short-term effects of intravitreal versus posterior subtenon injection of triamcinolone acetonide for diabetic macular edema. METHODS This is a prospective and interventional study. Sixty eyes of 60 patients who had diffuse diabetic macular edema were assigned to receive a single intravitreal injection (4 mg) or a single posterior subtenon injection (40 mg) of triamcinolone acetonide. The central retinal thickness was measured using optical coherent tomography before injection and at 1 and 3 months after injection. Visual acuity and intraocular pressure (IOP) were also measured. RESULTS Both intravitreal and posterior subtenon injections of triamcinolone acetonide resulted in significant improvements in visual acuity at 1 month and 3 months after injection. Both groups resulted in a significant decrease in central macular thickness (CMT) at 1 month and 3 months post-injection. IOP in the intravitreal injection group was significantly higher than in the posterior subtenon injection group at 3 months after injection. CONCLUSIONS The posterior subtenon injection of triamcinolone acetonide had a comparable effect to the intravitreal triamcinolone injection and showed a lower risk of elevated IOP. Posterior subtenon injection of triamcinolone acetonide may be a good alternative for the treatment of diffuse diabetic macular edema.