title: Peripapillary Retinal Nerve Fiber Layer Swelling Predicts Peripapillary Atrophy in a Primate Model of Nonarteritic Anterior Ischemic Optic Neuropathy.
abstract: OBJECTIVE
  To determine the relationship between peripapillary retinal nerve fiber layer (PRNFL) swelling and eventual PRNFL atrophy, and between PRNFL swelling/atrophy and neural function, in a nonhuman primate model of nonarteritic anterior ischemic optic neuropathy (pNAION).
  
  
  METHODS
  pNAION was induced in five normal, adult male rhesus monkeys by laser activation of intravenously injected rose bengal at the optic nerve head. Spectral-domain optical coherence tomography measurements of the PRNFL were performed at baseline; 1 day; 1, 2, and 4 weeks; and several later times over a period of an additional 2 to 3 months. Simultaneous pattern-reversal electroretinograms (PERGs) and visual evoked potentials (VEPs) were recorded and color fundus photographs taken at the same time points.
  
  
  RESULTS
  In all cases, initial PRNFL swelling was associated with atrophy, and the greater the initial swelling, the greater the degree of eventual atrophy (r = 0.65, P = 0.0002). The change in PRNFL thickness closely correlated with VEP amplitude loss (r = 0.90), although this relationship was only a strong trend (P = 0.083). Furthermore, VEP amplitude loss closely correlated with PERG N95 amplitude loss (r = 0.80, P = 0.00002).
  
  
  CONCLUSIONS
  In our model of human NAION, the degree of initial PRNFL swelling correlated with the severity of atrophy. Areas that did not swell developed little to no atrophy. The amount of PRNFL loss was reflected in VEP and PERG N95 amplitude reductions.
authors: Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States.
authors: Mary A
authors: MA
authors: Johnson
authors: The Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States.
authors: Neil R
authors: NR
authors: Miller
authors: Department of Veterinary Resources, University of Maryland School of Medicine, Baltimore, Maryland, United States.
authors: Theresa
authors: T
authors: Nolan
authors: Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States 4Department of Anatomy & Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland, United States.
authors: Steven L
authors: SL
authors: Bernstein
mesh_terms: D000818:Animals; D001284:Atrophy; D004195:Disease Models, Animal; D004596:Electroretinography; D008253:Macaca mulatta; D008269:Macular Edema / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D009898:Optic Disk / Q000473:pathology*; D018917:Optic Neuropathy, Ischemic / Q000150:complications / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*