Trans-Tenon's retrobulbar injection of triamcinolone acetonide for diffuse diabetic macular edema

To determine whether a trans-Tenon's retrobulbar injection of triamcinolone acetonide (TA) is a safe and effective treatment for diffuse diabetic macular edema.

Thirty-nine eyes of 30 diabetic patients with persistent macular edema were treated with 20 mg of TA injection. Central macular thickness (CMT) determined by optical coherence tomography (OCT) and visual acuity were evaluated before the injection and at 1, 2, 3, and 6 months, and up to 1 year in some eyes, after the injection.

The CMT decreased significantly from 478 +/- 129 microm (mean +/- SD) before injection to 316 +/- 102 microm at 1 month, 307 +/- 104 microm at 2 months, and 275 +/- 89 microm at 3 months after a single injection of TA. A 20% reduction of CMT from the initial value was maintained by a single injection of TA in 27 of 39 eyes (69.2%) at 3 months, in 14 of 22 eyes (63.6%) at 6 months, and in 5 of 7 eyes at 12 months. A recurrence of macular edema was observed in 10% of the eyes at 3 months, and in 22.7% at 6 months. The 17 eyes in which vitrectomy had been carried out had a more significant improvement in CMT than the eyes without vitrectomy.

A 20-mg trans-Tenon's retrobulbar TA injection is a safe and effective treatment for diabetic macular edema.