Aim To evaluate the optical coherence tomography angiography (OCTA) features of fellow eyes of patients with unilateral choroidal neovascularisation (CNV) associated with chronic central serous chorioretinopathy (CSCR).

Methods Medical records of patients with chronic CSCR who had undergone OCT angiography of both the eyes were reviewed. Patients with evidence of unilateral CNV detected by conventional imaging (OCT, fluorescein angiography and/or indocyanine green angiography) were included in the study. The OCT and OCTA characteristics of fellow eyes were analysed.

Results Forty patients (80 eyes—40 fellow eyes) with chronic CSCR with evidence of CNV in one eye were included. Mean age of the patients was 54.9±9.9 years and 82.5 % were males. Twenty-five (62.5%) fellow eyes had flat irregular pigment epithelial detachment on OCT, out of which 21 had internal hyper-reflectivity. A definite vascular network was picked up by OCTA in 9 of these 40 fellow eyes (22.5%) which was not detected on conventional imaging. In addition, two eyes had an ill-defined hyper-reflectivity, which could not be classified as a definite network at that point of time. The networks detected on OCTA in fellow eyes were mostly inactive, suggesting a subclinical neovascularisation.

Conclusion One-fourth of fellow eyes showed vascular network which could not be diagnosed on conventional imaging which highlights the importance of imaging both the eyes of chronic CSCR for early detection of CNV using OCTA. Further longitudinal studies are needed to assess the clinical course of such subclinical vascular networks in CSCR.