Quantitative Analysis of Choroidal Vascular Structures and Anatomical Changes in Pachychoroid Spectrum Diseases Using ultra-widefield SS-OCTA

This study utilized ultra-widefield swept-source optical coherence tomography angiography (UWF SS-OCTA) to quantitatively assess and compare choroidal blood flow structures and anatomical changes in eyes affected by central serous chorioretinopathy (CSC), pachychoroidal neovasculopathy (PNV), and uncomplicated pachychoroid (UCP). Additionally, we examined the distribution patterns of vortex veins across the three patient groups and conducted a preliminary investigation into the origin of choroidal neovascularization (CNV) in PNV. A total of 44 patients with CSC, 38 with PNV, and 46 with UCP were included in the analysis. Three-dimensional data were obtained from scans with dimensions of 20 mm vertically by 24 mm horizontally and a scan depth of 6 mm, covering nine subfields. The results demonstrated higher choroidal vessel volume per unit area (mCVV/a), choroidal vascularity index (CVI), and choroidal thickness (CT) in CSC eyes, while the PNV group exhibited similarities with the UCP group. Notably, PNV eyes showed the lowest foveal choriocapillaris density, suggesting that PNV and CSC may represent a continuous pathological spectrum, whereas UCP could be considered either a precursor to CSC or a remission stage following CSC resolution. CNV in PNV may result from choriocapillaris occlusion and ischemia due to mechanical compression by hypertrophic choroidal vessels. These findings provide valuable insights into choroidal structure analysis, hemodynamics within the pachychoroid spectrum disease (PSD), and the pathogenesis of CNV in PNV, thereby contributing to the understanding of shared etiologies within the PSD spectrum.