title: [Post-actinic retrobulbar optic neuropathy].
abstract: BACKGROUND
  Radiation optic neuropathy (RON) is a rare, unpredictable, late complication of radiotherapy secondary to obliterative endarteritis. Tumor recurrence has to be ruled out by a clinical and neuroradiological examination.
  
  
  METHODS
  Five patients with RON were investigated by magnetic resonance imaging (MRI) during 1992.
  
  
  RESULTS
  Radiation-induced lesions of the intracranial visual pathways were easily visible on MRI. Without Gadolinium, a sectorial swelling was detectable, which markedly enhanced with Gadolinium. Intracranial optic nerve was affected in 5/5 cases, optic chiasm in 3/5 cases, and optic tract in 2/5 cases.
  
  
  CONCLUSIONS
  MRI is the examination of choice when RON is suspected: it will easily delineate the extent of the lesion, and compression/infiltration by a recurrent tumor will be formally ruled out. A segmental swelling of visual pathway with marked Gadolinium enhancement on MRI is highly suggestive of radionecrosis.
authors.affiliation: Hôpital Ophtalmique Jules Gonin, Lausanne.
authors.forename: F X
authors.initials: FX
authors.lastname: Borruat
authors.forename: N J
authors.initials: NJ
authors.lastname: Schatz
authors.forename: J S
authors.initials: JS
authors.lastname: Glaser
mesh_terms: D016371:Cranial Irradiation; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000473:pathology / Q000528:radiation effects*; D009902:Optic Neuritis / Q000175:diagnosis*; D011832:Radiation Injuries / Q000175:diagnosis*; D011879:Radiotherapy Dosage; D014792:Visual Acuity / Q000528:radiation effects; D014794:Visual Fields / Q000528:radiation effects
vernacular_title: Neuropathie optique rétrobulbaire post-actinique.