Changes in the Iris and retinal vessel on optical coherence tomography angiography after intravitreal anti-vascular endothelial growth factor in diabetic macular edema

Abstract

Abstract Objectives Analyze quantitative changes of iris and retinal vessels in diabetic macular edema (DME) after intravitreal anti-vascular endothelial growth factor (anti-VEGF) and evaluate their correlations. Methods This was a case-cohort study. A total of 26 eyes of DME patients received anti-VEGF treatments and were reviewed three times of follow-up. Images of iris and retinal vessels were obtained before and after treatment and the area density of the vessel (VAD) and the density of the vessel skeleton (VSD) were quantitatively analyzed. Results There was no significant change in the iris VAD after the third injection (p > 0.05), but the VSD of iris decreased (p ＜0.05). Further linear regression analysis showed that the difference between postoperative and pretreatment iris VSD was negatively correlated with baseline(R = 0.793, B = -1.242, p = 0.000), but not with age, sex, and baseline visual acuity (all p > 0.05). Conclusions Iris vessels are more sensitive to anti-VEGF than retinal vessels.