To investigate the relationship between idiopathic choroidal neovascularisation (CNV) and choroidal watershed zones (CWZs) using indocyanine green angiography (ICGA).

The medical records and ICGA findings of 44 patients (44 eyes) diagnosed with idiopathic CNV were reviewed.

CWZs, defined as hypofluorescence that disappeared during the early phase of ICGA, were classified, and the findings were compared with those of a control group of 30 eyes.

The topographical relationship between CWZs and CNV was evaluated. Visual acuity and recurrence were analysed according to the CWZ classification.