Randomized trial of peribulbar triamcinolone acetonide with and without focal photocoagulation for mild diabetic macular edema - A pilot study

Objective: To provide pilot data on the safety and efficacy of anterior and posterior sub-Tenon injections of triamcinolone either alone or in combination with focal photocoagulation in the treatment of mild diabetic macular edema (DME). Design: Prospective, phase II, multicenter, randomized clinical trial. Participants: One hundred nine patients (129 eyes) with mild DIME and visual acuity 20/40 or better. Methods: The participants were assigned randomly to receive either focal photocoagulation (n = 38), a 20-mg anterior sub-Tenon injection of triamcinolone (n = 23), a 20-mg anterior sub-Tenon injection followed by focal photocoagulation after 4 weeks (n = 25), a 40-mg posterior sub-Tenon injection of triamcinolone (n = 21), or a 40-mg posterior sub-Tenon injection followed by focal photocoagulation after 4 weeks (n = 22). Follow-up visits were performed at 4, 8, 17, and 34 weeks. Main Outcome Measures: Change in visual acuity and retinal thickness measured with optical coherence tomography (OCT). Results: At baseline, mean visual acuity in the study eyes was 20/25 and mean OCT central subfield thickness was 328 mu m. Changes in retinal thickening and in visual acuity were not significantly different among the 5 groups at 34 weeks (P = 0.46 and P = 0.94, respectively). There was a suggestion of a greater proportion of eyes having a central subfield thickness less than 250 mu m at 17 weeks when the peribulbar triamcinolone was combined with focal photocoagulation. Elevated intraocular pressure and ptosis were adverse effects attributable to the injections. Conclusions: In cases of DIME with good visual acuity, peribulbar triamcinolone, with or without focal photocoagulation, is unlikely to be of substantial benefit. Based on these results, a phase III trial to evaluate the benefit of these treatments for mild DME is not warranted.