title: Assessment of Optic Pathway Structure and Function in Patients With Compression of the Optic Chiasm: A Correlation With Optical Coherence Tomography.
abstract: The purpose of this study was to investigate correlations between retinal fiber thickness measured by optical coherence tomography (OCT) and anterograde functional and structural differences in the optic pathway of patients with compression of the optic chiasm. Our hypothesis was that loss of visual acuity caused by chronic compressive pathologies may lead to an irreversible decline in vision because of permanent neurodegeneration of the optic radiations and visual cortex.
  
  
  
  Quantitative OCT, functional magnetic resonance imaging (MRI) and diffusion tensor MRI measurements were made in 17 patients being surgically treated for chiasmal compression.
  
  
  
  In our study we found that surgically irreversible visual field defects and reduced retinal nerve fiber layer thickness were significantly associated with lower fractional diffusion anisotropy and higher diffusivities in optic radiations and less functional MRI activation in the visual cortex.
  
  
  
  Damage to the retinal nerve fiber layer is associated with downstream structural and functional degradation of the optic pathway. This may be related to trans-synaptic degeneration and the fact that these factors are important potential imaging biomarkers for predicting visual recovery after surgical decompression.
authors.affiliation: Epworth Medical Imaging Epworth Hospital, Richmond, Victoria, Australia 2Department of Radiology, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Pramit M
authors.initials: PM
authors.lastname: Phal
authors.affiliation: Department of Radiology, The University of Melbourne, Parkville, Victoria, Australia 3Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Steward
authors.affiliation: Department of Neurosurgery, Alfred Health, Prahran, Victoria, Australia.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Nichols
authors.affiliation: Epworth Medical Imaging Epworth Hospital, Richmond, Victoria, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: Kokkinos
authors.affiliation: Department of Radiology, The University of Melbourne, Parkville, Victoria, Australia 3Department of Radiology, Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Desmond
authors.affiliation: Department of Ophthalmology, The University of Auckland, Auckland, New Zealand.
authors.forename: Helen
authors.initials: H
authors.lastname: Danesh-Meyer
authors.affiliation: Department of Neurosurgery, The University of Melbourne, Parkville, Victoria, Australia 7Department of Neurosurgery, Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors.forename: Yuval Z
authors.initials: YZ
authors.lastname: Sufaro
authors.affiliation: Department of Neurosurgery, The University of Melbourne, Parkville, Victoria, Australia 7Department of Neurosurgery, Royal Melbourne Hospital, Parkville, Victoria, Australia.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Kaye
authors.affiliation: Department of Anatomy and Neuroscience, Melbourne Neuroscience Institute, The University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Bradford A
authors.initials: BA
authors.lastname: Moffat
mesh_terms: D016022:Case-Control Studies; D019299:Decompression, Surgical; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D009408:Nerve Compression Syndromes / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D009897:Optic Chiasm / Q000473:pathology* / Q000503:physiopathology; D009900:Optic Nerve / Q000473:pathology / Q000503:physiopathology; D009901:Optic Nerve Diseases / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D041623:Tomography, Optical Coherence; D014794:Visual Fields