title: Electroretinographic abnormalities in multiple sclerosis: possible role for retinal autoantibodies.
abstract: BACKGROUND
  Multiple sclerosis (MS) has been associated with inflammation of the uveal tract, suggesting an immunological link between the uvea and central nervous system (CNS) in this disease. The retina is embryologically derived from the CNS, and it is conceivable that retinal antigens may also be recognized by the immune system in MS. Electroretinographic abnormalities, as well as retinal autoantibodies, have previously been described in MS. We performed this study to further explore the possibility of retinal autoimmunity in MS.
  
  
  METHODS
  Thirty-four patients with clinically definite MS and thirty-seven healthy controls were recruited. All patients and controls had standard electroretinographic (ERG) testing done, as well as a brightflash ERG protocol to isolate rod photoreceptor function. Patient and control sera were analyzed for the presence of antiretinal antibodies using Western blot techniques.
  
  
  RESULTS
  We found statistically significant differences between MS patients and controls in four ERG parameters. In the MS group, implicit times of the rod-cone b-wave response, cone b-wave response, and rod photoreceptor response were increased. The amplitudes of the photopic oscillatory potentials were reduced in the MS group. Patients with the highest titres of retinal autoantibodies had delayed rod-cone b-wave implicit times and diminished photopic oscillatory potential amplitudes.
  
  
  CONCLUSIONS
  We report ERG evidence of retinal dysfunction in patients with MS. We also report the first use of the brightflash ERG protocol in MS, which demonstrated rod photoreceptor dysfunction. Patients with the highest antiretinal antibody titres had abnormal ERG recordings. Retinal autoimmunity is a possible explanation for these observed ERG abnormalities in MS patients.
authors.affiliation: Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON, Canada.
authors.forename: Farzin
authors.initials: F
authors.lastname: Forooghian
authors.forename: Melanie
authors.initials: M
authors.lastname: Sproule
authors.forename: Carol
authors.initials: C
authors.lastname: Westall
authors.forename: Lynn
authors.initials: L
authors.lastname: Gordon
authors.forename: Guy
authors.initials: G
authors.lastname: Jirawuthiworavong
authors.forename: Kaori
authors.initials: K
authors.lastname: Shimazaki
authors.forename: Paul
authors.initials: P
authors.lastname: O'Connor
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000276:immunology*; D015153:Blotting, Western; D018450:Disease Progression; D004596:Electroretinography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications / Q000276:immunology / Q000503:physiopathology*; D011379:Prognosis; D017949:Retinal Cone Photoreceptor Cells / Q000276:immunology* / Q000503:physiopathology; D012164:Retinal Diseases / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D017948:Retinal Rod Photoreceptor Cells / Q000276:immunology* / Q000503:physiopathology
chemical_list: D001323:Autoantibodies