Some studies have found an increased prevalence of MNV after treatment with laser 8 9 or photodynamic therapy (PDT) 9 10 in CSC, which may be caused by rupture of the BM after laser therapy or choroidal ischaemia and excessive vascular endothelial growth factor (VEGF) production after PDT. 5 In recent research, CSC has been considered a part of the pachychoroid spectrum disease and may be complicated by the secondary formation of exudative MNV 6 7 however, the mechanism of secondary MNV has not yet been determined. 3 4 A panel of experts recently recommended a new definition of macular neovascularisation (MNV) to replace the old term of choroidal neovascularisation. 1 2 Choroidal neovascularisation refers to abnormalities of blood vessels derived from choroidal capillaries, which penetrate through a break in Bruch’s membrane (BM) and proliferate into the space between the BM and the RPE or neurosensory retina. 1 Chronic CSC or recurrent CSC frequently results in severe irreversible vision damage caused by photoreceptor impairment and RPE atrophy. Correspondence to Dr Yuki Komuku Ĭentral serous chorioretinopathy (CSC) typically manifests as serous detachment of the neurosensory retina, often below the macula, resulting from a retinal pigment epithelium (RPE) barrier disorder and pachychoroid owing to hyperpermeable vessels.7 Department of Ophthalmology, Sapporo City General Hospital, Sapporo, Japan.6 Department of Ophthalmology, Nara Medical University, Kashihara, Nara, Japan.5 Department of Ophthalmology and Visual Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.4 Department of Ophthalmology, Kobe University Graduate School of Medicine, Kobe, Japan.3 Department of Ophthalmology, Kagoshima University, Kagoshima, Kagoshima, Japan.2 Japan Clinical Retina Study (JCREST) group, Kagoshima, Kagoshima, Japan.1 Department of Ophthalmology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan.