Trans-Tenon's retrobulbar triamcinolone acetonide infusion for refractory diabetic macular edema after vitrectomy

Abstract

Purpose: To evaluate the efficacy and safety of trans-Tenon's retrobulbar triamcinolone acetonide (TA) infusion for the treatment of refractory diabetic macular edema (DME) after vitrectomy.

Methods: After topical anesthesia, 20 eyes from 20 patients with persistent DME after pars plana vitrectomy were treated with trans-Tenon's retrobulbar infusion of 40 mg TA through an inferotemporal approach. The mean duration (+/-SD) between vitrectomy and trans-Tenon's retrobulbar TA infusion was 11.4+/-7.9 months. The mean follow-up period (+/-SD) after trans-Tenon's retrobulbar TA infusion was 13.3+/-2.8 months.

Results: At 1 week after trans-Tenon's retrobulbar TA infusion, the mean central retinal thickness (+/-SD) measured by optical coherence tomography was 381+/-99 mum, which was a statistically significant decrease in comparison with the preoperative thickness (555+/-112 mum) (P<0.001). Additional trans-Tenon's retrobulbar TA infusions were performed in ten eyes (50%), due to the recurrence of DME at 6.6+/-3.0 months after the first TA infusion. At the final examination, macular edema resolved in 13 (65%), improved in four (20%), and remained unchanged in three (15%) of the 20 eyes. At 1 month after trans-Tenon's retrobulbar TA infusion, the mean laser flare value (+/-SD) was 9.6+/-3.0 photon/ms, which was a statistically significant decrease in comparison with the preoperative value (15.5+/-5.9 photon/ms) (P<0.01). Furthermore, in ten eyes (50%) with recurrent DME, re-elevated laser flare values were observed prior to the recurrence of DME. The final best-corrected Snellen visual acuity improved by two or more lines in nine eyes (45%), and remained unchanged in 11 eyes (55.0%). IOP elevation equal to or higher than 21 mmHg was observed in three (15%) of the 20 eyes with TA infusion, and was controlled by topical medications. No other injection-related complications were observed.

Conclusion: Trans-Tenon's retrobulbar TA infusion is an effective and safe method for the treatment of refractory DME, which is present even after vitrectomy.