Abnormal choroidal flow on optical coherence tomography angiography in central serous chorioretinopathy

Importance Analysing choroidal flow in central serous chorioretinopathy (CSC) with novel device. Background To examine the abnormal morphology of choriocapillary flow with optical coherence tomography angiography (OCTA) according to the presence of subretinal fluid (SRF) in CSC. Design A hospital-based retrospective study. Participants We analysed OCTA results of 68 eyes (68 patients) diagnosed as CSC with or without SRF (active and resolved CSC, respectively) at the Asan Medical Center. Methods We classified OCTA choriocapillary images into three pattern groups: mixed perfusion, hyper-perfusion and normal perfusion. Data analysis included age, follow-up duration, treatment modalities, number of treatments, subfoveal choroidal thickness and SRF height. Main Outcome Measures The relationship between CSC activity and choriocapillary pattern. Results Abnormal choroidal flow (mixed and hyper-perfusion) was more frequently found in eyes with active CSC (100%) than resolved CSC (47.5%, P < 0.001). In active CSC eyes, mixed perfusion was predominant (71.4%), while hyper-perfusion was predominant in those with resolved CSC (73.7%). Eyes with recently resolved CSC (SRF absorption present for <2 months) had abnormal choriocapillary flow more often than the remaining eyes with resolved CSC (83.3% vs 32.1%, P = 0.005). Resolved CSC eyes with abnormal choriocapillary flow demonstrated more recurrence than eyes with normal choriocapillary flow (42.1% vs 9.5%, P = 0.017). Conclusions and Relevance The pattern of choriocapillary flow abnormalities on OCTA can indicate CSC disease activity. Because eyes with resolved CSC showing abnormal choroidal flow have a high recurrence rate, they should be carefully followed-up.