title: Enlargement of internal carotid artery aneurysm presenting with severe visual sequela: a case report and anatomy review.
abstract: BACKGROUND
  The majority of intracranial aneurysms arise from the internal carotid artery (ICA) circulation. The proximity of cranial nerves II to VI to the pathway of the internal carotid artery make them susceptible to damage from an ICA aneurysm, which may cause a variety of neurologic effects. Although vision loss is a relatively uncommon sequela of an ICA aneurysm, compression of the optic nerve by an aneurysm can cause visual field loss, decreased visual acuity, or both.
  
  
  METHODS
  An 85-year-old man with sudden-onset, painless, and profound monocular vision loss from compression of the optic nerve caused by an enlarged internal carotid artery aneurysm is described. Clinical presentation, detection, and treatment of an ICA aneurysm are discussed.
  
  
  CONCLUSIONS
  An intracranial aneurysm or other compromise to the cerebral circulation should be ruled out in cases of vision loss that remain unexplained after a thorough ocular health evaluation, especially in patients with a history of cardiovascular disease or head injury.
authors.affiliation: Southern Arizona VA Health Care System, Tucson, Arizona, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Mendez Roberts
authors.forename: Amy L
authors.initials: AL
authors.lastname: Grimes
mesh_terms: D000369:Aged, 80 and over; D000783:Aneurysm / Q000150:complications*; D002340:Carotid Artery Diseases / Q000150:complications* / Q000175:diagnosis; D002343:Carotid Artery, Internal / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009408:Nerve Compression Syndromes / Q000209:etiology; D009900:Optic Nerve; D014786:Vision Disorders / Q000209:etiology*