Application of Novel Quantitative Measurement of Iris Angiography in Diabetic Retinopathy

Abstract Introduction: The purpose of this study was to explore the application of a novel quantitative measurement of iris angiography (IA) in diabetic retinopathy (DR). Methods: This was a single-center, cross-sectional prospective study. Totally 168 consecutive patients with diabetic mellitus (DM) were involved into this study from May 2016 to December 2020, 168 subjects were devided into 3 groups, 32 non-retinopathy patients,96 non-proliferative diabetic retinopathy patients(NPDR), and 40 proliferative diabetic retinopathy (PDR) patients. All patients underwent ophthalmologic examination, such as best corrected visual acuity, intraocular pressure, slit-lamp microscopy, gonioscopy, ultra-wide-field fundus photography, fluorescein angiography of the iris (IFA), and indocyanine green angiography of the iris (IIGA). The starting of iris vascular leakage time(LT) was recorded, and the range of pupil fluorescein leakage was measured by a novel measurement. Results: LT of iris in non-retinopathy, non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR) groups were 33.14 ± 3.03s, 32.45 ± 5.17s, and 25.67 ± 5.03s, respectively. The LT in the PDR group was significantly faster than those in the NPDR and non-retinopathy groups (P=0.000). The iris pupil leakage range (LR) of the non-retinopathy, NPDR, and PDR groups were 21.21 ± 30.06, 62.48 ± 42.17, and 141.31 ± 73.61°, and LR in PDR groups were largest among all groups (P=0.000). Neovascularization of the iris (NVI) was detected in 8 eyes (26.7%) in the PDR group. No NVI was found in non-retinopathy and NPDR groups.Conclusions: The novel quantitative measurement of IA can be used to evaluate the severity of diabetic iridopathy (DI) accurately and detect invisible NVI as early as possible to provide a basis for the formulation of personalized treatment for DR patients.