Comprehensive analysis of pachyvessel morphology in central serous chorioretinopathy using multimodal imaging

The purpose of this study was to identify characteristic morphological features of large choroidal blood vessels (pachyvessels) in eyes with central serous chorioretinopathy (CSC) using enhanced depth imaging (EDI) optical coherence tomography (OCT). A total of 116 eyes from 58 patients with CSC and 116 eyes from 58 age- and gender-matched healthy subjects were included. EDI OCT raster scan images were analyzed for the presence of characteristic features of pachyvessels and accompanying retinal pigment epithelial (RPE) abnormalities, with additional imaging data obtained from fluorescein angiography (FA) and indocyanine green angiography (ICGA). Severely dilated pachyvessels abutting the RPE-Bruch's membrane-choriocapillaris complex, referred to as the "Hanging Drop (HD) sign," were identified in all acute CSC eyes and 86.4% of CSC eyes overall. The HD sign was observed either with ("active") or without ("inactive") vascular wall hyperreflectivity along the RPE-Bruch's membrane-choriocapillaris complex. The active HD sign was present exclusively in CSC eyes (56.1%) and was significantly more frequent in acute CSC compared to chronic and resolved CSC (88.9%, 47.4%, and 17.6%, respectively; P < 0.05). While the inactive HD sign was also more common in CSC eyes than in unaffected fellow eyes and healthy eyes (77.3%, 30.0%, and 9.5%, respectively), its prevalence did not differ significantly among CSC eyes with varying clinical conditions (P > 0.05). RPE abnormalities were consistently observed in OCT images showing the active HD sign. These findings suggest that characteristic morphological features of pachyvessels discerned using EDI OCT raster scans can aid in the diagnosis and evaluation of CSC.