title: Clinically isolated syndromes suggestive of multiple sclerosis: an optical coherence tomography study.
abstract: BACKGROUND
  Optical coherence tomography (OCT) is a simple, high-resolution technique to quantify the thickness of retinal nerve fiber layer (RNFL), which provides an indirect measurement of axonal damage in multiple sclerosis (MS). This study aimed to evaluate RNFL thickness in patients at presentation with clinically isolated syndromes (CIS) suggestive of MS.
  
  
  METHODS
  This was a cross-sectional study. Twenty-four patients with CIS suggestive of MS (8 optic neuritis [ON], 6 spinal cord syndromes, 5 brainstem symptoms and 5 with sensory and other syndromes) were prospectively studied. The main outcome evaluated was RNFL thickness at CIS onset. Secondary objectives were to study the relationship between RNFL thickness and MRI criteria for disease dissemination in space (DIS) as well as the presence of oligoclonal bands in the cerebrospinal fluid.
  
  
  RESULTS
  Thirteen patients had decreased RNFL thickness in at least one quadrant. Mean RNFL thickness was 101.67±10.72 µm in retrobulbar ON eyes and 96.93±10.54 in unaffected eyes. Three of the 6 patients with myelitis had at least one abnormal quadrant in one of the two eyes. Eight CIS patients fulfilled DIS MRI criteria. The presence of at least one quadrant of an optic nerve with a RNFL thickness at a P<5% cut-off value had a sensitivity of 75% and a specificity of 56% for predicting DIS MRI.
  
  
  CONCLUSIONS
  The findings from this study show that axonal damage measured by OCT is present in any type of CIS; even in myelitis forms, not only in ON as seen up to now. OCT can detect axonal damage in very early stages of disease and seems to have high sensitivity and moderate specificity for predicting DIS MRI. Studies with prospective long-term follow-up would be needed to establish the prognostic value of baseline OCT findings.
authors.affiliation: Neuroimmunology and Multiple Sclerosis Unit, Department of Neurology, Idipaz Health Research Institute, University Hospital La Paz, Madrid, Spain. orejacbn@gmail.com
authors.forename: Celia
authors.initials: C
authors.lastname: Oreja-Guevara
authors.forename: Susana
authors.initials: S
authors.lastname: Noval
authors.forename: Juan
authors.initials: J
authors.lastname: Alvarez-Linera
authors.forename: Laura
authors.initials: L
authors.lastname: Gabaldón
authors.forename: Beatriz
authors.initials: B
authors.lastname: Manzano
authors.forename: Beatriz
authors.initials: B
authors.lastname: Chamorro
authors.forename: Exuperio
authors.initials: E
authors.lastname: Diez-Tejedor
mesh_terms: D000293:Adolescent; D000328:Adult; D001369:Axons / Q000473:pathology*; D003430:Cross-Sectional Studies; D003711:Demyelinating Diseases / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis*; D009410:Nerve Degeneration; D009412:Nerve Fibers / Q000473:pathology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D055815:Young Adult