title: The origins of polypoidal choroidal vasculopathy.
abstract: OBJECTIVE
  There are two theories on the pathogenesis of polypoidal choroidal vasculopathy (PCV): variants in choroidal neovascularisation (CNV) and inner choroidal vessel abnormalities. On indocyanine green angiography (IGA) with a video camera system, PCV has a characteristic appearance, but inadequate image quality has made detailed interpretation difficult. This study aims to improve imaging, using confocal scanning laser ophthalmoscopy (SLO), to elucidate the pathogenesis of PCV.
  
  
  METHODS
  High speed IGA with confocal SLO of 45 eyes (44 patients) showed typical PCV findings of a branching vascular network and polypoidal lesions.
  
  
  RESULTS
  Vessels comprising branching networks began to fill simultaneously with the surrounding choroidal arteries in 38 eyes. Small numbers of vessels filling within a branching network, in the arterial and arteriovenous phases of IGA, showed focal dilatation, constriction, and tortuousity. Vessel abnormalities, corresponding to polypoidal lesions, existed within a network in eight eyes and included loops similar in calibre to network vessels, and numerous microaneurysmal dilatations of small vessels. Vessel pulsation was seen in 24 eyes.
  
  
  CONCLUSIONS
  PCV is caused by inner choroidal vessel abnormalities, not CNV.
authors.affiliation: Surugadai Hospital, Nihon University, Kanda, Chiyoda-ku, Tokyo, Japan. yuzawam@med.nihon-u.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yuzawa
authors.forename: R
authors.initials: R
authors.lastname: Mori
authors.forename: A
authors.initials: A
authors.lastname: Kawamura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001808:Blood Vessels / Q000002:abnormalities; D002829:Choroid / Q000098:blood supply*; D015862:Choroid Diseases / Q000209:etiology* / Q000473:pathology; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D007208:Indocyanine Green; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods; D011673:Pulsatile Flow; D012163:Retinal Detachment / Q000209:etiology; D012166:Retinal Hemorrhage / Q000209:etiology
chemical_list: D007208:Indocyanine Green