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

PURPOSE: To evaluate changes in retinal and choroidal circulation after subtenon triamcinolone acetonide (TA) injection for diabetic macular edema. DESIGN: Prospective interventional case series. METHODS: 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 T (as an indicator of early filling velocity of choroid) were obtained with image analysis software. RESULTS: Choroidal T values before and I 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. CONCLUSION: Subtenon TA injection transiently influences choroidal blood flow.