title: Progressive retinal structure abnormalities in multiple system atrophy.
abstract: BACKGROUND
  Objective measures of disease progression that can be used as endpoints in clinical trials of MSA are necessary. We studied retinal thickness in patients with MSA and assessed changes over time to determine its usefulness as an imaging biomarker of disease progression.
  
  
  METHODS
  This was a cross-sectional study including 24 patients with MSA, 20 with PD, and 35 controls, followed by a longitudinal study of 13 MSA patients. Patients were evaluated with high-definition optical coherence tomography and the Unified Multiple System Atrophy Rating Scale. Evaluations were performed at baseline and at consecutive follow-up visits for up to 26 months.
  
  
  RESULTS
  MSA subjects had normal visual acuity and color discrimination. Compared to controls, retinal nerve fiber layer (P = 0.008 and P = 0.001) and ganglion cell complex (P = 0.013 and P = 0.001) thicknesses were reduced in MSA and PD. No significant differences between MSA and PD were found. Over time, in patients with MSA, there was a significant reduction of the retinal nerve fiber layer and ganglion cell complex thicknesses, with estimated annual average losses of 3.7 and 1.8 μm, respectively.
  
  
  CONCLUSIONS
  Visually asymptomatic MSA patients exhibit progressive reductions in the thickness of the retinal nerve fiber layer and, to a lesser extent, in the macular ganglion cell complex, which can be quantified by high-definition optical coherence tomography. Specific patterns of retinal nerve fiber damage could be a useful imaging biomarker of disease progression in future clinical trials.
authors.affiliation: Dysautonomia Center, Department of Neurology, New York University School of Medicine, New York, New York, USA.|New England Eye Center, Tufts Medical Center, Tufts University, Boston, Massachusetts, USA.
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Mendoza-Santiesteban
authors.affiliation: Dysautonomia Center, Department of Neurology, New York University School of Medicine, New York, New York, USA.
authors.forename: Jose-Alberto
authors.initials: JA
authors.lastname: Palma
authors.affiliation: Dysautonomia Center, Department of Neurology, New York University School of Medicine, New York, New York, USA.
authors.forename: Jose
authors.initials: J
authors.lastname: Martinez
authors.affiliation: Dysautonomia Center, Department of Neurology, New York University School of Medicine, New York, New York, USA.
authors.forename: Lucy
authors.initials: L
authors.lastname: Norcliffe-Kaufmann
authors.affiliation: New England Eye Center, Tufts Medical Center, Tufts University, Boston, Massachusetts, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Hedges
authors.affiliation: Dysautonomia Center, Department of Neurology, New York University School of Medicine, New York, New York, USA.
authors.forename: Horacio
authors.initials: H
authors.lastname: Kaufmann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000502:physiology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000473:pathology* / Q000503:physiopathology; D012160:Retina / Q000473:pathology* / Q000503:physiopathology; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology
keywords: Parkinson disease; ganglion cell complex; multiple system atrophy; optical coherence tomography; retinal nerve fiber layer; unified multiple system atrophy rating scale