title: Optical coherence tomography in multiple sclerosis: thickness of the retinal nerve fiber layer as a potential measure of axonal loss and brain atrophy.
abstract: BACKGROUND
  Axonal distribution within the retinal nerve fiber layer (RNFL) measured by optical coherence tomography (OCT) correlates with axonal viability and integrity.
  
  
  OBJECTIVE
  To investigate correlations between RNFL and MRI measures of axonal loss in MS patients.
  
  
  METHODS
  Fifty one remitting-relapsing MS patients, 20 with a history of optic neuritis (MS-ON), 31 without optic neuritis (MS N-ON), and 12 healthy control subjects (HC) were included in the study. RNFL was measured by OCT and brain atrophy was assessed by MRI.
  
  
  RESULTS
  The average RNFL in the affected eye (AE) in the MS-ON group was significantly lower than the RNFL in the MS N-ON (p = 0.01) and in HC (p = 0.01). The average RNFL in the unaffected eye (UE) and RNFL in MS N-ON were also lower than HC, but this value did not achieve significance. In MS N-ON a lower average RNFL was associated with an increased T1 lesion volume (p = 0.03) and T2-lesion volume (p = 0.001). The RNFL in MS N-ON was also associated with a reduction of BPF and %gm fraction (p = 0.01, p = 0.02 respectively). In MS-ON there was a much weaker, non-significant correlation between RNFL thickness and T1, T2 volume, BPF, %gm and %wm fractions that might have resulted from a pronounced post-inflammatory local optic nerve atrophy in AE.
  
  
  CONCLUSIONS
  The RNFL measured by OCT may be useful as a surrogate marker for assessment of brain atrophy in MS.
authors.affiliation: Department of Neurology, Medical University of Lodz, Kopcińskiego 22, 90-153 Lodz, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Siger
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Dziegielewski
authors.forename: Lukasz
authors.initials: L
authors.lastname: Jasek
authors.forename: Marek
authors.initials: M
authors.lastname: Bieniek
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Nicpan
authors.forename: Jerzy
authors.initials: J
authors.lastname: Nawrocki
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Selmaj
mesh_terms: D000328:Adult; D001284:Atrophy; D001369:Axons / Q000473:pathology*; D001921:Brain / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009103:Multiple Sclerosis / Q000473:pathology*; D009412:Nerve Fibers / Q000473:pathology*; D009902:Optic Neuritis / Q000473:pathology; D012044:Regression Analysis; D012160:Retina / Q000473:pathology*; D041623:Tomography, Optical Coherence