title: Lesions in the posterior visual pathway promote trans-synaptic degeneration of retinal ganglion cells.
abstract: OBJECTIVE
  Retrograde trans-synaptic degeneration of retinal ganglion cell layer (GCL) has been proposed as one of the mechanisms contributing to permanent disability after visual pathway damage. We set out to test this mechanism taking advantage of the new methods for imaging the macula with high resolution by optical coherence tomography (OCT) in patients with lesions in the posterior visual pathway. Additionally, we explored the association between thinning of GCL as an imaging marker of visual impairment such as visual field defects.
  
  
  METHODS
  Retrospective case note review of patients with retrogeniculate lesions studied by spectral domain OCT of the macula and quadrant pattern deviation (PD) of the visual fields.
  
  
  RESULTS
  We analysed 8 patients with either hemianopia or quadrantanopia due to brain lesions (stroke  = 5; surgery  = 2; infection  = 1). We found significant thinning of the GCL in the projecting sector of the retina mapping to the brain lesion. Second, we found strong correlation between the PD of the visual field quadrant and the corresponding macular GCL sector for the right (R = 0.792, p<0.001) and left eyes (R = 0.674, p<0.001).
  
  
  CONCLUSIONS
  The mapping between lesions in the posterior visual pathway and their projection in the macula GCL sector corroborates retrograde trans-synaptic neuronal degeneration after brain injury as a mechanism of damage with functional consequences. This finding supports the use of GCL thickness as an imaging marker of trans-synaptic degeneration in the visual pathway after brain lesions.
authors.affiliation: The Institute of Ophthalmology and Center for Neuroimmunology, Institute of Biomedical Research August Pi Sunyer (IDIBAPS) - Hospital Clínic, Barcelona, Spain.
authors.forename: Johannes
authors.initials: J
authors.lastname: Keller
authors.affiliation: The Institute of Ophthalmology and Center for Neuroimmunology, Institute of Biomedical Research August Pi Sunyer (IDIBAPS) - Hospital Clínic, Barcelona, Spain.
authors.forename: Bernardo F
authors.initials: BF
authors.lastname: Sánchez-Dalmau
authors.affiliation: The Institute of Ophthalmology and Center for Neuroimmunology, Institute of Biomedical Research August Pi Sunyer (IDIBAPS) - Hospital Clínic, Barcelona, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Villoslada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012183:Retrograde Degeneration / Q000473:pathology* / Q000503:physiopathology; D012189:Retrospective Studies; D013569:Synapses / Q000473:pathology*; D014794:Visual Fields; D014795:Visual Pathways / Q000473:pathology*; D056969:Voltage-Sensitive Dye Imaging; D055815:Young Adult