Purpose: To quantitatively evaluate the inner and outer choroidal changes in the fellow eyes of patients with unilateral central serous chorioretinopathy (CSC).
Methods: We analyzed data from patients with a diagnosis of unilateral CSC who had structural optical coherence tomography (OCT) and swept-source OCT angiography obtained. An additional group of age-matched healthy patients was included for comparison. The main outcome measures were: (1) choriocapillaris flow deficits' quantitative metrics; (2) choroidal luminal (LCA) and stromal (SCA) areas; and (3) choroidal vascularity index.
Results: Fellow unaffected eyes from 60 patients with unilateral CSC and 30 healthy subjects were included in the analysis. Mean ± SD age was 47.5 ± 9.9 years in the unilateral CSC group and 50.7 ± 10.8 years in the control group (P = 0.410). In the structural OCT assessment, both the LCA and SCA were increased in the unilateral CSC group (0.33 ± 0.11 and 0.29 ± 0.10 mm2) compared with healthy controls (0.28 ± 0.08 and 0.27 ± 0.05 mm2), although only differences in LCA reached a statistical significance (P = 0.041 and P = 0.286 for LCA and SCA, respectively). The choroidal vascularity index was higher in CSC patients (53.7 ± 3.6 and 50.9 ± 5.5%, P = 0.045). In the OCT angiography evaluation, the choriocapillaris flow deficits' percentage and number were increased in those patients affected by unilateral CSC. In multiple regressions, the strongest association with choriocapillaris percentage of flow deficits was with the presence of pachychoroid pigment epitheliopathy signs in the study eye (P < 0.0001).
Conclusion: Our results corroborate the hypothesis that inner and outer choroidal changes affect both eyes of patients with unilateral disease.