Objective To quantitatively evaluate the changes of choroidal biomarkers in patients with central serous chorioretinopathy (CSC) and preliminarily explore its pathogenesis. MethodsClinical cross-sectional study. From July 2021 to December 2022, 74 eyes of 65 patients with CSC (CSC group) confirmed by ophthalmic examination at the First Affiliated Hospital of Zhengzhou University were included in the study. Among them, 46 patients (51 eyes) were male, 19 patients (23 eyes) were female. The duration from the onset of symptoms to the time of treatment was less than or equal to 3 months. A control group consisted of 40 healthy volunteers (74 eyes) matched in age and gender. Among them, 26 patients (50 eyes) were male, and 14 patients (24 eyes) were female. Using VG200D from Microimaging (Henan) Technology Co., Ltd., macular scanning source light coherence tomography angiography was performed, with scanning range 6 mm × 6 mm. According to the division of the diabetes retinopathy treatment research group, the choroid within 6 mm of the macular fovea was divided into three concentric circles centered on the macular fovea, namely, the central area with a diameter of 1 mm, the macular area with a diameter of 1-3 mm, and the surrounding area of the fovea with a diameter of 3-6 mm. The device comes with software to record the three-dimensional choroidal vascular index (CVI), choroidal vascular volume (CVV), perfusion area of the choroidal capillary layer (CFA), choroidal thickness (CT), and three-dimensional CVI, CVV, and CT in the upper, temporal, lower, and subnasal quadrants within 6 mm of the fovea. Quantitative data between the two groups were compared using an independent sample t-test. Qualitative data comparison line χ2 inspection. The value of receiver operating curve (ROC) analysis in predicting the occurrence of CSC, including CVI, CVV, CFA, and CT. ResultsCompared with the control group, the CVI (t=3.133, 4.814), CVV (t=7.504, 9.248), and CT (t=10.557, 10.760) in the central and macular regions of the affected eyes in the CSC group significantly increased, while the CFA (t=－8.206, －5.065) significantly decreased, with statistically significant differences (P＜0.05); CVI (t=7.129), CVV (t=10.020), and CT (t=10.488) significantly increased within 6 mm of the central fovea, while CFA (t=－2.548) significantly decreased, with statistically significant differences (P＜0.05). The CVI (t=4.980, 4.201, 4.716, 8.491), CVV (t=9.014, 7.156, 7.719, 10.730), and CT (t=10.077, 8.700, 8.960, 11.704) in the upper, temporal, lower, and lower nasal quadrants within 6 mm of the central fovea were significantly increased, with statistically significant differences (P＜0.05). In the CSC group, the maximum CVI and CVV were (0.39±0.10)% and (1.09±0.42) mm3, respectively, on the nasal side of the affected eye. Upper CT was (476.02±100.89) μm. The nasal side CVI, CVV, and CT have the largest changes. The ROC curve analysis results showed that the area under the curve of CT, CVV, and CVI within 6 mm of the central region, macular region, and fovea was over than 0.5. Subcentral CT was the most specific for the diagnosis of CSC. ConclusionChoroidal biomarkers CVI, CVV, and CT in CSC patients increase, while CFA decreases. Central CT is the most specific for the diagnosis of CSC.