The effect of subtenon triamcinolone acetonide injection for diabetic macular edema on retinal and choroidal circulation.

Abstract

To evaluate changes in retinal and choroidal circulation after subtenon triamcinolone acetonide (TA) injection for diabetic macular edema. Prospective interventional case series. Thirteen eyes of 13 patients with diabetic macular edema were studied. Fluorescein and indocyanine green angiograms were performed at three periods: before the injection and 1 week and 6 months after subtenon injection of TA (40 mg). Retinal arteriovenous passage time (as an indicator of retinal circulation) and choroidal tau (as an indicator of early filling velocity of choroid) were obtained with image analysis software. Choroidal tau values before and 1 week after subtenon TA injection were, respectively, 3.2 +/- 0.4 and 4.0 +/- 0.7 seconds, which showed a significant delay (P = .01, Wilcoxon signed-rank test). The delayed choroidal tau values returned to pretreatment level at 6 months after TA injection. In contrast, the arteriovenous passage time remained unchanged. Subtenon TA injection transiently influences choroidal blood flow.