title: Association between retinal nerve fiber layer thickness and magnetic resonance imaging findings and intelligence in patients with multiple sclerosis.
abstract: BACKGROUND
  Multiple Sclerosis (MS) is a neurological disease in which demyelination and axonal loss leads to progressive disability. Cognition impairment is among the most common complication. Studying axonal loss in the retina is a new marker for MS. The main goal of our study is to search for correlations between magnetic resonance imaging (MRI) findings and the retinal nerve fiber layer (RNFL) thickness at the macula and head of the optic nerve and Wechsler Adult Intelligence Scale-Revised (WAIS-R) Scores that assess multiple domains of intelligence, and to explore the relationship between changes in the RNFL thickness with intellectual and cognitive dysfunction.
  
  
  METHODS
  A prospective cross-sectional study was conducted at the University Hospital of Kashani, Isfahan, Iran, from September to December 2013. All patients were assessed with a full-scale intelligence quotient (IQ) on the WAIS-R. An optical coherence tomography study and brain MRI were performed in the same week for all the patients. Statistical analysis was conducted by using a bivariate correlation, by utilizing SPSS 20.0. A P value ≤ 0.05 was the threshold of statistical significance.
  
  
  RESULTS
  Examination of a 100 patients showed a significant correlation between the average RNFL thickness of the macula and the verbal IQ (P value = 0.01) and full IQ (P value = 0.01). There was a significant correlation between brain atrophy and verbal IQ.
  
  
  CONCLUSIONS
  The RNFL loss was correlated with verbal IQ and full IQ.
authors.affiliation: Isfahan Neurosciences Research Center, Alzahra Hospital, Isfahan, Iran ; Department of Neurology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Ashtari
authors.affiliation: Isfahan Neurosciences Research Center, Alzahra Hospital, Isfahan, Iran ; Department of Neurology, Medical School, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Parisa
authors.initials: P
authors.lastname: Emami
authors.affiliation: Department of Epidemiology, School of Health and Nutrition, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Akbari
keywords: Cognition; Wechsler adult intelligence scale-revised; intelligence quotient; multiple sclerosis; optic coherence tomography; retinal nerve fiber layer