title: Relationship between optical coherence tomography and electrophysiology of the visual pathway in non-optic neuritis eyes of multiple sclerosis patients.
abstract: OBJECTIVE
  Loss of retinal ganglion cells in in non-optic neuritis eyes of Multiple Sclerosis patients (MS-NON) has recently been demonstrated. However, the pathological basis of this loss at present is not clear. Therefore, the aim of the current study was to investigate associations of clinical (high and low contrast visual acuity) and electrophysiological (electroretinogram and multifocal Visual Evoked Potentials) measures of the visual pathway with neuronal and axonal loss of RGC in order to better understand the nature of this loss.
  
  
  METHODS
  Sixty-two patients with relapsing remitting multiple sclerosis with no previous history of optic neuritis in at least one eye were enrolled. All patients underwent a detailed ophthalmological examination in addition to low contrast visual acuity, Optical Coherence Tomography, full field electroretinogram (ERG) and multifocal visual evoked potentials (mfVEP).
  
  
  RESULTS
  There was significant reduction of ganglion cell layer thickness, and total and temporal retinal nerve fibre layer (RNFL) thickness (p<0.0001, 0.002 and 0.0002 respectively). Multifocal VEP also demonstrated significant amplitude reduction and latency delay (p<0.0001 for both). Ganglion cell layer thickness, total and temporal RNFL thickness inversely correlated with mfVEP latency (r = -0.48, p<0.0001 respectively; r = -0.53, p<0.0001 and r = -0.59, p<0.0001 respectively). Ganglion cell layer thickness, total and temporal RNFL thickness also inversely correlated with the photopic b-wave latency (r = -0.35, p = 0.01; r = -0.33, p = 0.025; r = -0.36, p = 0.008 respectively). Multivariate linear regression model demonstrated that while both factors were significantly associated with RGC axonal and neuronal loss, the estimated predictive power of the posterior visual pathway damage was considerably larger compare to retinal dysfunction.
  
  
  CONCLUSIONS
  The results of our study demonstrated significant association of RGC axonal and neuronal loss in NON-eyes of MS patients with both retinal dysfunction and post-chiasmal damage of the visual pathway.
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, Australia.
authors.forename: Prema
authors.initials: P
authors.lastname: Sriram
authors.affiliation: Brain and Mind Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Chenyu
authors.initials: C
authors.lastname: Wang
authors.affiliation: Concord Hospital, Sydney, Australia.
authors.forename: Con
authors.initials: C
authors.lastname: Yiannikas
authors.affiliation: St Vincent's Hospital, Sydney, Australia.
authors.forename: Raymond
authors.initials: R
authors.lastname: Garrick
authors.affiliation: Brain and Mind Research Institute, University of Sydney, Sydney, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Barnett
authors.affiliation: Royal North Shore Hospital, Sydney, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Parratt
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, Australia; Save Sight Institute, Department of Ophthalmology, University of Sydney, Sydney, Australia.
authors.forename: Stuart L
authors.initials: SL
authors.lastname: Graham
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, Australia; Save Sight Institute, Department of Ophthalmology, University of Sydney, Sydney, Australia.
authors.forename: Hemamalini
authors.initials: H
authors.lastname: Arvind
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, Australia; Save Sight Institute, Department of Ophthalmology, University of Sydney, Sydney, Australia.
authors.forename: Alexander
authors.initials: A
authors.lastname: Klistorner
mesh_terms: D000328:Adult; D001369:Axons / Q000502:physiology; D004596:Electroretinography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000503:physiopathology*; D012160:Retina / Q000503:physiopathology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology*; D014795:Visual Pathways / Q000503:physiopathology*