Characteristics of the choroidal vascular structure at lesions in central serous chorioretinopathy

To investigate the characteristics of choroidal vascular structure at lesions in eyes with central serous chorioretinopathy (CSC). Medical records from July 2020 to August 2023 were reviewed. En face optical coherence tomography (OCT) images were obtained by manually adjusting the segmentation lines, using Bruch’s membrane as reference plane, downward to capture the choroidal vessels beneath the inner choroidal thinning. The vascular networks were classified as Y (bifurcation), L (inflection) or X (crossing) based on their shapes. Then the smallest angle was measured at each bifurcation, inflection, or intersection point in Y/L/X-shaped vascular networks. Two hundred and fifteen eyes of 159 CSC patients were included. Of these eyes, 191 eyes (88.84%) displayed Y/L/X-shaped dilated vascular networks beneath the inner choroidal thinning in en face OCT images, taken at a depth of 108.85 ± 22.26 μm from Bruch Membrane and with a median thickness of 31(range: 10–99) µm. Overall, there were 297 Y-shaped vascular networks with a median included angle of 86.66° (range: 24.56°-118.90°), 100 L-shaped vascular networks with a mean included angle of 95.59° ± 18.84°, and 21 X-shaped vascular networks with a mean included angle of 78.75° ± 7.65°. Nearly 90% of CSC eyes exhibit Y/L/X-shaped dilated vascular networks with included angles close to a right angle beneath the inner choroidal thinning in en face OCT images. This suggests that focal dilation of choroidal vessels may be associated with near-right angles in bifurcated, curved, or crossed vessels, indicating a susceptible local anatomic architecture for the development of CSC.