To investigate choriocapillaris (CC) blood flow in unaffected fellow eyes of patients with central serous chorioretinopathy (CSC) using quantitative optical coherence tomography angiography (OCTA) analysis.

Case-control study.

Patients with acute, recurrent, or persistent CSC, along with healthy sex- and age-matched subjects, were included. Objective assessment of CC blood flow was performed using OCTA measurements. Total area of flow signal voids was quantified at baseline, 3 months, and 6 months. Active serous retinal detachment (SRD) was considered as a potential source of false-positive flow impairment; affected eyes were therefore excluded at onset and during follow-up, if this finding was unresolved at the time of measurement.

Sixty patients with CSC and 60 control subjects were included in this study. The total average flow signal void area was significantly higher in the unaffected eyes of CSC patients at baseline (2.70 ± 0.53 mm² vs 2.23 ± 0.43 mm², P < .001). At 3 months, the total average flow signal void area was greater in the affected eyes of CSC patients with resolved SRD compared with unaffected eyes (3.25 ± 0.77 mm² vs 2.67 ± 0.68 mm², P < .001). This total average flow signal void area was larger in unaffected eyes at baseline in recurrent/persistent cases of CSC compared to acute forms (3.74 ± 0.66 mm² vs 2.93 ± 0.69 mm², P = .01).

Vascular abnormalities in CSC involve CC hypoperfusion, suggestive of a primary choroidopathy including ischemic processes. These microvascular flow deficits may constitute one of a number of underlying subclinical changes preceding CSC and other pachychoroid spectrum disorders.