Optical coherence tomography angiography of central serous chorioretinopathy: quantitative evaluation of the vascular pattern and capillary flow density

Background This study aimed to evaluate the vascular pattern and capillary flow density (CFD) map on optical coherence tomography angiography (OCTA) images of patients affected by central serous chorioretinopathy (CSC). Methods In this retrospective cohort study, OCTA (AngioVue RTVue XR Avanti, Optovue) 3 x 3 mm macula scans of both eyes of patients with CSC were taken at baseline; the images were segmented and compared with OCTA scans of fellow eyes without CSC as well as age-matched healthy subjects. OCTA images were processed by quantitative textural analysis (ImageJ software) to provide an objective grading of choroidal capillary alterations. The texture of OCTA images was examined by the autocorrelation method. Results In eyes with CSC (40 eyes), we found six different morphological patterns of the choriocapillaris layer vasculature (CCL), likely corresponding to different grades of OCT choroidal hyporeflectivity and OCTA reduction of the decorrelation signal. Moreover, the OCTA capillary flow density map revealed capillary depletion in the superficial capillary plexus (p value =0.0023), in the deep vascular network (p value= <0.0001), and in the CCL (p value =0.0001). Such findings were not observed in healthy subjects (13 eyes). Conclusions OCTA in CSC is a useful tool that allows the identification of the clinical type of CSC by means of specific CCL patterns. Moreover, CFD depletion is observed in association with the inner retinal layers, pointing to an involvement of the inner blood retinal barrier in CSC. According to our results, it is plausible that the patterns observed herein may correlate to the different clinical subtypes of the disease.