OCT Angiography of the Choriocapillaris in Central Serous Chorioretinopathy: A Quantitative Subgroup Analysis.

INTRODUCTION: To quantify optical coherence tomography angiography (OCTA) signal changes at the level of the choriocapillaris (CC) in patients with different stages of central serous chorioretinopathy (CSC) and to explore any correlation between subretinal fluid (SRF) and retinal pigment epithelium (RPE) alterations and the OCTA CC signal.

METHODS: One hundred one CSC eyes and 42 healthy control eyes were included in this retrospective study. CSC patients were allocated into four groups: acute, non-resolving, chronic atrophic and inactive CSC. CC OCTA images (AngioPlex® , Zeiss) were automatically quantified using an image-processing algorithm. Spatial correlation analysis of OCTA signals was performed by overlapping macular edema heatmaps and fundus autofluorescence images with corresponding OCTA images.

RESULTS: Active CSC subgroups demonstrated significantly more increased and decreased flow pixels in the CC compared with controls (p < 0.0001). No significant OCTA changes were seen within the active CSC groups or between the inactive and healthy subgroup. Spatial correlation analysis revealed a decreased OCTA signal in the SRF area and an increased signal outside the SRF area in acute CSC. Areas of RPE atrophy co-localized with areas of increased choriocapillaris OCTA signal, while areas with RPE alterations exhibited a normal signal compared with unaffected RPE.

CONCLUSION: The decreased OCTA signal in the area of SRF in acute CSC could be evidence of localized CC hypoperfusion or due to shadowing artifacts. The missing CC OCTA changes in altered RPE adjacent to atrophy argues against CC injury. Studies with higher resolution and optimized image acquisition are warranted to further validate our findings.