%0 Journal Article %T Differences in Choroidal Structures Between Idiopathic and Steroid %A Hideki Koizumi %A Ichiro Maruko %A Shozo Sonoda %A Taiji Sakamoto %A Takahiko Izumi %A Tomohiro Iida %A Yohei Takahashi %J Journal of VitreoRetinal Diseases %@ 2474-1272 %D 2019 %R 10.1177/2474126418818348 %X The purpose of this article is to investigate the differences in intrachoroidal structures between eyes with idiopathic central serous chorioretinopathy (CSC) and those with steroid-induced CSC. Thirty eyes of 30 patients with idiopathic CSC and 17 eyes of 15 patients with steroid-induced CSC were studied. Cross-sectional swept-source optical coherence tomography images of eyes with idiopathic and steroid-induced CSC were retrospectively analyzed by the manual layer delineation technique and by the binarization technique. The mean subfoveal choroidal thickness (SCT) was not significantly different between the eyes with idiopathic CSC (408.0 ¡À 106.6 ¦Ìm) and those with steroid-induced (389.9 ¡À 105.4 ¦Ìm; P = .67) CSC. Manual layer delineation showed that the mean ratio of the large choroidal vessel layer thickness to the SCT was significantly higher in eyes with idiopathic CSC (0.874 ¡À 0.070) than in eyes with steroid-induced CSC (0.828 ¡À 0.083; P = .02). The binarization method showed that the mean ratio of the luminal areas to the choroidal areas centered at the fovea was significantly higher in eyes with idiopathic CSC (0.747 ¡À 0.064) than in eyes with steroid-induced CSC (0.701 ¡À 0.046; P = .01). The intrachoroidal structures in steroid-induced CSC were different from those in idiopathic CSC. These findings suggest different pathophysiologic mechanisms may be involved in the pathogenesis of these 2 entities %K binarization %K central serous chorioretinopathy %K choriocapillaris %K choroid %K choroidal layer %K choroidal thickness %K choroidal vessel %K steroid %U https://journals.sagepub.com/doi/full/10.1177/2474126418818348