We defined the relationships between initial choroidal conditions and their dynamics and exudative changes during anti-vascular endothelial growth factor (anti-VEGF) therapy in polypoidal choroidal vasculopathy (PCV). One hundred treatment-naïve eyes of 100 patients with PCV treated for 24 months at Keio University Hospital with intravitreal ranibizumab or aflibercept monotherapy (three injections and PRN thereafter) were retrospectively analyzed. Wet macula risk after three induction injections, which affected visual prognosis, was predicted by initial pachyvessels in the choroid (foveal greatest vertical choroidal vessel diameter [CVD] ≥180 μm) and pachychoroid (central choroidal thickness [CCT] ≥220 μm) recorded by optical coherence tomography. The risk for recurrent exudative change was greater in the pachyvessel groups irrespective of presence or absence of pachychoroid. Mean CVD and CCT decreased with anti-VEGF therapy when achieving a dry macula, suggesting that exudative changes are regulated by VEGF. Mean CVD and CCT at remission were greater in patients with initial pachyvessels and pachychoroid than in those without; the basal levels of CVD and CCT most likely represent VEGF-unrelated conditions. CVD increase preceded CCT increase and recurrent exudative changes, suggesting that the VEGF-related CVD increase may regulate CCT and exudative change; and that CVD may be a biomarker of exudative change.