title: Fellow eye changes in optic neuritis correlate with the risk of multiple sclerosis.
abstract: BACKGROUND
  Recent studies demonstrate early diffuse central nervous system (CNS) inflammation in patients with multiple sclerosis (MS). The clinically unaffected (fellow) eye of patients with unilateral optic neuritis (ON) may reflect the status of normal-appearing white matter in the CNS, which can be assessed electrophysiologically.
  
  
  OBJECTIVE
  To study the relationship between electrophysiological parameters in the fellow eye of ON patients, and risk of conversion to MS.
  
  
  METHODS
  Forty-eight consecutive patients with acute unilateral ON were examined 12 months after ON of which 14 had MS, 19 remained high risk (HR) for MS, and 15 had low risk (LR) for MS according to McDonald's criteria. Twenty-five age-matched controls were also tested. Amplitude and latency of multifocal visual evoked potential (mfVEP) in the fellow eyes of patients at 12 months were analyzed and compared with controls.
  
  
  RESULTS
  Average mfVEP amplitude was 240 +/- 35, 232 +/- 36, 181 +/- 38, and 169 +/- 48 nV for controls, LR, HR, and MS groups respectively. Average mfVEP latency for controls, LR, HR, and MS patients was 139.7 +/- 5.5, 141.7 +/- 3.6, 145.9 +/- 8.9, and 152.0 +/- 9.9 ms respectively.
  
  
  CONCLUSIONS
  The magnitude of latency prolongation and amplitude decline 12 months after the initial episode was proportional to the risk of MS. The prognostic significance of these changes as predictors of subsequent MS should be investigated longitudinally.
authors.affiliation: Department of Ophthalmology, Save Sight Institute, University of Sydney, Sydney, Australia. sasha@eye.usyd.edu.au
authors.forename: A
authors.initials: A
authors.lastname: Klistorner
authors.forename: H
authors.initials: H
authors.lastname: Arvind
authors.forename: T
authors.initials: T
authors.lastname: Nguyen
authors.forename: R
authors.initials: R
authors.lastname: Garrick
authors.forename: M
authors.initials: M
authors.lastname: Paine
authors.forename: S
authors.initials: S
authors.lastname: Graham
authors.forename: C
authors.initials: C
authors.lastname: Yiannikas
mesh_terms: D000328:Adult; D001921:Brain / Q000473:pathology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005071:Evoked Potentials; D005123:Eye / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology; D009902:Optic Neuritis / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D010775:Photic Stimulation; D011930:Reaction Time; D018570:Risk Assessment; D013116:Spinal Cord / Q000473:pathology; D013997:Time Factors; D014792:Visual Acuity