Relationships Between Choroidal Characteristics and Disease Activity in Acute Central Serous Chorioretinopathy

Purpose: To investigate choroidal characteristics during active and resolved (presence and absence of subretinal fluid, respectively) central serous chorioretinopathy (CSC), and to clarify their relationships with disease activity.Methods: The choroidal characteristics of 33 CSC and 35 age-matched control eyes were analyzed using optical coherence tomography (OCT). The CSC group included eyes with subretinal fluid at baseline. Horizontal OCT images passing through the macula, and data for age, sex, visual acuity, and refractive error, were acquired. The subretinal fluid height and subfoveal choroidal thickness were measured. The total choroidal area (TCA), luminal choroidal area (LCA), and stromal choroidal area (SCA) were measured using ImageJ software. The choroidal vascularity index (CVI) was defined as the ratio of LCA to TCA. The measurements were repeated after 5.6 months following complete absorption of the subretinal fluid. The choroidal characteristics were compared between the active and resolved phases.Results: The CSC group had significantly greater choroidal thickness, TCA, LCA, and CVI values compared to the control group. The choroidal thickness, TCA, LCA, and SCA were significantly reduced after resolution compared to active CSC. However., the decrease in SCA was greater than that in LCA, which led to a significant increase in CVI (68.6 ± 3.2 vs. 71.6 ± 3.0, p < 0.001) after CSC resolution.Conclusions: CVI measurements may allow estimation of CSC disease activity. TCA, LCA, SCA, and CVI changes may indicate whether the disease is active or resolved, and thus guide CSC treatment.