title: Visual outcome in bilateral nonarteritic anterior ischemic optic neuropathy.
abstract: BACKGROUND
  Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of visual loss in the older population. Bilateral NAION is a well-documented entity; however, no study to date has compared the visual outcome between affected eyes.
  
  
  METHODS
  The authors retrospectively reviewed the charts of 99 patients with diagnoses of NAION over 3 1/2 years. In the 23 patients with bilateral involvement, 16 were included in the study for analysis of final visual outcome between affected eyes. Snellen acuity, Ishihara color plates, and Humphrey automated perimetry were evaluated as the parameters of visual function. Descriptive analysis of the outcome between affected eyes for each parameter is presented as a frequency distribution of pre-defined groups. Statistical significance is established using nonparametric tests.
  
  
  RESULTS
  Bilateral NAION was found in 23% (23/99) of the patients studied. The authors identified a high percent agreement between eyes with regard to visual acuity (81% within 3 Snellen lines), color vision (69% within 3 plates), and Humphrey visual field (75% within 5 decibels of mean deviation). Additionally, there was a statistically significant correlation between affected eyes for all three visual parameters: visual acuity (P = 0.043), color vision (P = 0.001), and Humphrey visual field (P = 0.039).
  
  
  CONCLUSIONS
  The authors found a high percent agreement and statistically significant correlation in final outcome between affected eyes of patients with bilateral NAION for visual acuity, color vision, and visual field loss. With a larger series, it may be possible to predict the visual outcome of the second affected eye based on the parameters of the first eye.
authors.affiliation: Anheuser-Busch Eye Institute, St. Louis, MO 63104, USA.
authors.forename: M I
authors.initials: MI
authors.lastname: Boone
authors.forename: G G
authors.initials: GG
authors.lastname: Massry
authors.forename: R A
authors.initials: RA
authors.lastname: Frankel
authors.forename: J B
authors.initials: JB
authors.lastname: Holds
authors.forename: S M
authors.initials: SM
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000502:physiology*; D003119:Color Perception Tests; D005260:Female; D013700:Giant Cell Arteritis; D006801:Humans; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000503:physiopathology*; D011379:Prognosis; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology*; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*