BackgroundTo compare the characteristics and treatment responses of polypoidal choroidal vasculopathy (PCV) between highly myopic and non-highly myopic eyes.MethodsThis retrospective cohort study included patients diagnosed with PCV at the clinic of National Taiwan University Hospital between 2013 and 2019. The diseased eyes were grouped per refractive error and axial length at diagnosis. Imaging data were used to retrieve the PCV characteristics, and electronic medical records were used to retrieve the treatment responses.ResultsAmong 116 eyes with PCV, 11 eyes of 10 patients were highly myopic; seven of these patients were women. All highly myopic eyes showed a thin subfoveal choroid, while three eyes had a pachychoroid phenotype with significant focal choroidal thickening. After treatment with either intravitreal anti-vascular endothelial growth factor (VEGF) injections, photodynamic therapy (PDT), or both, best-corrected visual acuity was better in the high-myopia group at 1 year. Visual acuity at presentation and the presence of feeder vessels were found to be predictors of the visual outcome.ConclusionsIn this study we reported, to the best of our knowledge, the largest cohort of PCV in highly myopic eyes to date. Female predominance, lower incidence of subretinal haemorrhage, and a thin choroid with a focal pachychoroid phenotype were found to characterise PCV in highly myopic eyes. Visual acuity transiently improved after either anti-VEGF monotherapy or combination therapy with PDT.