title: Angiography of experimental autoimmune uveoretinitis with ultrastructural correlation.
abstract: BACKGROUND
  Indocyanine green (ICG) angiography has been used to evaluate posterior uveitis in the clinical setting, despite the shortage of data on possible pathological correlates of observed findings.
  
  
  METHODS
  We used both ICG angiography and fluorescein angiography to examine rats that developed a mild form of experimental autoimmune uveoretinitis (EAU) induced by immunization with interphotoreceptor retinoid-binding protein (IRBP). Angiography was performed on days 9, 10, 11 and 23 after IRBP immunization, and freshly enucleated eyes obtained on the same days were examined histopathologically by light microscopy and transmission electron microscopy.
  
  
  RESULTS
  Diffuse dilatation and tortuosity of the retinal vessels was observed by both ICG and fluorescein angiography, with leakage from these vessels in focal areas in the periphery. In addition, deep hyperfluorescent spots in the central posterior pole, not associated with retinal vessels, were observed by ICG angiography only. These corresponded to Dalen-Fuchs-like nodules on funduscopy. On histopathological examination, eyes showed inflammatory cell infiltration around retinal vessels, disorganization of outer retinal layers, focal subretinal accumulations of cells (resembling Dalen-Fuchs nodules), and diffuse inflammatory cell infiltration in the choroid. Ultrastructural examination of a Dalen-Fuchs-like nodule revealed a mound of monocytes, appearing to contain phagosomes of lipofuscin and phospholipids, sandwiched between transformed retinal pigment epithelium (RPE) cells with disrupted apical processes and loss of basal interdigitation.
  
  
  CONCLUSIONS
  These results suggest that ICG angiography may be useful in delineating certain abnormalities at the level of the RPE, in association with posterior ocular inflammation, that cannot be observed by fluorescein angiography alone.
authors.affiliation: Department of Ophthalmology, Tokyo Medical College Hospital, Japan. aokada@po.iijnet.or.jp
authors.forename: A A
authors.initials: AA
authors.lastname: Okada
authors.forename: H
authors.initials: H
authors.lastname: Goto
authors.forename: T
authors.initials: T
authors.lastname: Mizusawa
authors.forename: K
authors.initials: K
authors.lastname: Morimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Ebihara
authors.forename: M
authors.initials: M
authors.lastname: Usui
mesh_terms: D000818:Animals; D001327:Autoimmune Diseases / Q000139:chemically induced / Q000473:pathology*; D002829:Choroid / Q000648:ultrastructure; D005136:Eye Proteins; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D007208:Indocyanine Green; D008297:Male; D010857:Pigment Epithelium of Eye / Q000648:ultrastructure; D051381:Rats; D011917:Rats, Inbred Lew; D012171:Retinal Vessels / Q000648:ultrastructure; D012173:Retinitis / Q000139:chemically induced / Q000473:pathology*; D012177:Retinol-Binding Proteins; D014605:Uveitis / Q000139:chemically induced / Q000473:pathology*; D000099214:Retinol-Binding Proteins, Interstitial
chemical_list: D005136:Eye Proteins; D007208:Indocyanine Green; D012177:Retinol-Binding Proteins; D000099214:Retinol-Binding Proteins, Interstitial