PURPOSE: To evaluate posterior subtenon injection of triamcinolone acetonide for refractory diabetic macular edema (DME). DESIGN: Retrospective, interventional, case series. METHODS: SETTING: Clinical practice. PATIENT POPULATION: Patients with persistent clinically significant DME involving the center of the fovea 3 or more months after one or more treatments of focal macular photocoagulation were included. Exclusion criteria were a history of corticosteroid,responsive intraocular pressure (lop) rise, intraocular surgery within 3 months, and any laser treatment within I month. PROCEDURE: All patients received an ophthalmic history and examination including best-corrected Snellen visual acuity, IOP measurement, anterior segment examination including evaluation of lens status with LOCS II criteria, dilated fundus examination, and a posterior subtenon injection of 40 mg triamcinolone acetonide at baseline. Patients were reevaluated at 1, 3, 6, and 12 months after injection. RESULTS: Seventy-three injections were performed in 63 eyes of 50 patients. The mean baseline visual acuity was 20/80. Mean visual acuity significantly improved to 20/50 at 1 month, then stabilized to 20/65 at 3 months 20/68 at 6 months, and 20/63 at 12 months. Complications were rare, with a transient significant rise in intraocular pressure at the 3-montb evaluation and ptosis in two patients. CONCLUSIONS: Visual acuities remained stable or improved over a 12-month period after posterior sub, tenon triamcinolone injections for refractory DME. There was a statistically significant improvement in visual acuity at 1 month.