Objective To observe the ultrasonographic features of idiopathic uveal effusion syndrome (IUES). MethodsA retrospective controlled study. From January 2012 to December 2023, 13 patients with IUES (26 eyes) diagnosed by ophthalmology examination in Department of Ophthalmonogy of Beijing Tongren Hospital (IUES group) and 22 healthy people with 30 eyes (control group) were included in the study. Both eyes of all participants were examined by color Doppler ultrasound (CDU) and ultrasonic biomicroscopy (UBM). The thickness of the ocular wall at 300 μm on the temporal side of the optic disc was measured by CDU. UBM was used to measure the thickness of the nasal and temporal scleral processes. Corneal thickness (CT), anterior chamber depth (AD), lens thickness (LT) and axial length (AL) were measured by A-mode ultrasound. There were no significant differences in age (t=0.842), sex component ratio (χ2=0.540), eye difference (χ2=0.108) and AL (t=0.831) between IUES group and control group (P＞0.05). The CDU and UBM imaging features and biometrics of IUES affected eyes were observed. Independent sample t test was used for comparison between groups. ResultsCDU examination results showed that in 26 eyes of IUES group, choroidal detachment occurred in 20 eyes (76.9%, 20/26), which showed arc-shaped band echo connected with peripheral and equatorial eye wall echo, with uniform low echo area below, and blood flow signal could be seen on the band echo. The echo thickened and decreased in 4 eyes (15.3%, 4/26). Nine eyes (33.3%, 9/26) were accompanied by retinal detachment, which showed that the posterior pole vitreous echo was connected to the optic disc echo, and the blood flow signal was seen on the ribbon echo. UBM results showed ciliary detachment in 22 eyes (84.7%, 22/26), showing a spongy thickening of the ciliary body with interlamellar echo separation and an echoless area between the sclera. Ciliary body echo thickened and decreased in 2 eyes (7.7%, 2/26). Shallow space between ciliary body and sclera was observed in 2 eyes (7.7%, 2/26). Compared with the control group, CT (Z=2.054), LT (Z=1.867), scleral thickness (Z=2.536) and ocular wall thickness (Z=2.094) were thickened in IUES group, and AD (Z=1.888) were decreased, with statistical significance (P＜0.05). ConclusionsThe CDU of IUES is characterized by a thickened echo of the ocular wall and a uniform low echo area under the detached choroid. UBM is characterized by a spongy thickening of the ciliary body echo with interlaminar echo separation.