title: Microvascular changes in the retrobulbar optic nerve in idiopathic intracranial hypertension.
abstract: OBJECTIVE
  To examine the microvascular changes in the retrobulbar optic nerve in idiopathic intracranial hypertension (PTC).
  
  
  METHODS
  Both optic nerves from a 29-year-old man with a two year history of PTC were examined histologically and morphometrically. A semi-automated image analysis system and paraphenylenediamine (PPD) stain were employed to resolve sufficiently the microvascular images for counts and measurement.
  
  
  RESULTS
  There were 150 vessels distributed in the optic nerves which revealed the following: The average lumen of the vessels in outer sectors were larger than those of the inner sector vessels (168.17 microns 2 vs. 46.99 microns 2; p = 0.0338; OD; and 251.96 microns 2 vs. 130.02 microns 2; p = 0.029; OS) while in the normal control optic nerve the outer and inner area lumens were reversed in size-differential, but this did not show a statistical difference. The thickness of the PTC optic nerve vessel walls in the outer sectors was also greater than that of the walls in the inner sectors (4.95 microns vs. 2.67 microns; p = 0.013; OD and 5.25 microns vs. 3.34 microns; p = 0.019; OS); the same measurements in the normal optic nerve showed a reversed ratio, which was opposite that of the experimental group and but not statistically different.
  
  
  CONCLUSIONS
  This pattern of microvascular changes is consistent with the selective axonal loss in the peripheral area of each optic nerve as much more severe than that in the inner sectors.
authors.affiliation: Zhongshan Ophthalmic Center, Sun Yat-sen University of Medical Sciences, 54 Xianlie Road, Guangzhou 510060, China.
authors.forename: X
authors.initials: X
authors.lastname: Gu
authors.forename: X H
authors.initials: XH
authors.lastname: Lin
authors.forename: H G
authors.initials: HG
authors.lastname: Saddati
authors.forename: Y
authors.initials: Y
authors.lastname: Zhong
authors.forename: H Y
authors.initials: HY
authors.lastname: Hsu
authors.forename: A A
authors.initials: AA
authors.lastname: Sadun
mesh_terms: D000328:Adult; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008833:Microcirculation / Q000648:ultrastructure; D009900:Optic Nerve / Q000098:blood supply* / Q000648:ultrastructure; D010211:Papilledema / Q000473:pathology / Q000503:physiopathology; D010655:Phenylenediamines; D011559:Pseudotumor Cerebri / Q000473:pathology / Q000503:physiopathology*; D014794:Visual Fields
chemical_list: D010655:Phenylenediamines; C029728:4-phenylenediamine