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 μm, which was a statistically significant decrease in comparison with the preoperative thickness (555±112 μm)
(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.