To analyze the optical coherence tomography (OCT) imaging characteristics in patients with Coats disease and their value in predicting macular fibrosis.

A nested case-control study was performed.A total of 43 patients (43 eyes) diagnosed with Coats disease through color fundus photography, ocular B-scan ultrasonography, fundus fluorescein angiography, and spectral-domain OCT examination were enrolled from January 2008 to October 2021 at the Xijing Hospital.Among them, there were 40 males and 3 females, aged from 2 to 60 years old, with a median age of 13 years.Macular fibrosis was used as an indicator of poor prognosis, and patients were divided into two groups based on whether macular fibrosis occurred at the end of follow-up.The differences in OCT characteristics between two groups were compared and logistic regression analysis was used to identify the risk factors for macular fibrosis.This study adhered to the Declaration of Helsinki and was approved by the Ethics Committee of Xijing Hospital of Fourth Military Medical University (No.KY20202009-C-1).

The OCT clinical features of 43 cases of Coats disease included intraretinal hard exudates in 43 eyes (100%), subretinal fluid in 21 eyes (48.8%), macular cysts in 17 eyes (27.9%), subretinal exudates in 9 eyes (20.9%), anterior retinal hyperreflective dots in 7 eyes (16.3%), epiretinal membrane in 21 eyes (48.8%), and intraretinal fluid in 22 eyes (51.2%).In color fundus photos of 41 eyes, 38 eyes (93.0%) had hard exudates distributed in the posterior pole and 27 eyes (65.9%) had the mid-peripheral region.OCT examination showed that hard exudates were distributed in the inner nuclear layer in 35 eyes (81.4%) and the outer nuclear layer in 33 eyes (76.7%).Among 21 eyes with exudative retinal detachment detected by OCT, 9 eyes (42.9%) were detected by fundus photography and 18 eyes (85.7%) were detected by B-scan ultrasonography.The proportions of eyes with subretinal fluid and subretinal exudates were higher in the macular fibrosis group than in the non-macular fibrosis group, and the differences were statistically significant (χ²=20.755, P<0.001; χ²=6.133, P=0.013).Logistic regression analysis showed that the presence of subretinal fluid was a risk factor for macular fibrosis (odds ratio=48.345, 95% confidence interval: 4.272-547.066, P=0.002).

OCT examination can detect subretinal fluid, subretinal exudates, macular cysts, macular exudates, and hyperreflective spots in the retina of patients with Coats disease.Subretinal fluid is a risk factor for macular fibrosis.

Coats disease; Tomography, optical coherence; Subretinal fluid; Retinal exudation; Macular fibrosis; Inflammation; Prognosis