ObjectiveTo observe and analyze the multimodal imaging characteristics of fundus in patients with idiopathic retinal vasculitis, aneurysms and neuroretinitis (IRVAN) syndrome. MethodsA retrospective study. From June 2015 to March 2024, 6 patients (11 eyes) diagnosed with IRVAN syndrome in Shaanxi Eye Hospital were included in the study. All patients underwent examinations including best-corrected visual acuity (BCVA), color fundus photography, fluorescein fundus angiography (FFA), optical coherence tomography (OCT) and OCT angiography (OCTA). At the same time, FFA combined with indocyanine green angiography (ICGA) was performed in 6 eyes. Follow-up ranged from 2 to 23 months. Multimodal imaging features were analyzed retrospectively. The number of retinal aneurysms detected by FFA, ICGA, and OCTA was compared by using the Wilcoxon signed-rank test. ResultsIn 11 eyes of 6 cases, a total of 1 male (2 eyes) and 5 females (9 eyes) with the mean age of (31.67±12.91) years were included in this cohort. Color fundus photography showed clear optic disc boundaries in 5 eyes, optic disc aneurysms in 8 eyes, retinal aneurysms in 4 eyes; exudation in 9 eyes, localized around aneurysms. On OCT, vitreous high reflective dots and epiretinal membrane on optic disc in all 11 eyes, and macular epiretinal membrane in 3 eyes were revealed. FFA showed optic disc aneurysms and retinal aneurysms in 9 eyes, late optic disc hyperfluorescence in 11 eyes; local arterial leakage in 3 eyes, local venous leakage in 8 eyes, non-perfusion area in all 11 eyes, and retina neovascularization in 3 eyes. Optic disc aneurysms and retinal aneurysms in 5 eyes (total 18 aneurysms) on ICGA were shown compared with optic disc aneurysms in 4 eyes and retinal aneurysms in 5 eyes (total 13 aneurysms) on simultaneous FFA. OCTA revealed neovascularization on the optic disc in 2 eyes, optic disc aneurysmsin 8 eyes, retinal aneurysms in 1 eye (total 2 aneurysms); while on simultaneous FFA, optic disc aneurysms in 8 eyes and retinal aneurysms in 3 eyes (total 5 aneurysms) with no optic disc were displayed. During OCTA follow-up, new aneurysms appeared at the bifurcation of arteries with an increasing angle between them and non-perfusion area enlargement on FFA. Compared with FFA and ICGA, OCTA in detecting the number of aneurysms had no statistics significance (Z=−1.342, −1.342; P＞0.05). ConclusionMultimodal imaging can demonstrate characteristics of IRVAN syndrome, ICGA provides superior visualization of optic disc and retinal aneurysms, while OCTA confirms optic disc neovascularization and enlargement of artery angles at arterial bifurcations.