Efficacy of sub-Tenon’s capsule injection of triamcinolone acetonide for refractory diabetic macular edema after vitrectomy

To determine whether or not a sub-Tenon’s capsule injection of triamcinolone acetonide(TA) is an effective treatment for refractory diabetic macular edema after vitrectomy. Methods : Thirty-nine eyes of 26 patients with diabetic macular edema were injected with 20 mg TA into the sub-Tenon’s capsule. The central macular thickness (CMT) measured by an optical coherence tomography (OCT) and visual acuities were compared between pre-treatment and 1, 3 months post -treatment. Results : The decrease in the mean CMT between the baseline (435 μm) and 1month (326 μm) or 3months (303 μm) time points was statistically significant. Seven eyes (70%) at 1 month and 3 months post-treatment in the vitrectomized eyes or PPV(pars plana vitrectomy)(+) group, 15 eyes(52%) at 1 month, and 19 eyes (66%) at 3 months in the non-vitrectomized eyes or PPV(-)group maintained 20% reduction in CMT from pre-treatment with a single injection of TA. The recurrence of macular edema was observed in 1 eye (14%) in the PPV(+)group, and 3 eyes (16%) in the PPV(-)group. Conclusion : The sub-Tenon’s capsule injection of TA was effective for refractory diabetic macular edema after vitrectomy. In addition, it was suggested that the treatment of vitrectomized eyes was more effective than that of non-vitrectomized eyes.