Amaurosis fugax

• Overview:

  • Sudden, short-term, painless loss of vision in one eye
  • Also known as a retinal transient ischaemic attack
  • Most commonly occurs in adults over 50 and typically lasts for a few minutes
  • Sometimes associated with thrombotic vascular events originating from the internal carotid arteries and therefore considered a possible warning sign for an impending stroke
• Causes:

  • Most common - Stenosis or occlusion of the internal carotid artery
  • Giant cell arteritis
  • Optic neuritis
  • Demyelinating disorders e.g. MS
  • Severe head injuries
• Narrowing or occlusion of the internal carotid artery or central retinal artery:

  • Leading to decreased blood supply to the retina, optic nerve, or other visual pathways
  • Most commonly due to carotid artery disease - arthrosclerosis
  • Sometimes parts of the plaque can detach from the inner lining of the artery ad clog smaller blood vessels such as the central retinal artery
• Risk factors:

  • Diabetes
  • Smoking
  • Cocaine use
  • Advancing age - increased rates hypertension and and hyperlipidaemia
• Signs/symptoms:

  • Experience of curtain passing across the eye that ultimately blocks their vision
  • Affect on visual field varies - can be the entire visual field or only part of it
  • Visual loss is often painless
  • Lasts for a few seconds - minutes
  • May experience one or multiple episodes
• Examination:

  • Assessment of any cardiovascular risk factors
  • Examination of the optic nerve and disc
  • Auscultation of the carotid arteries - bruits
• Investigations:

  • Bloods - ESR, CRP may be done to rule out GCA
  • Doppler ultrasound - if carotid artery disease is suspected
  • MRI or CTA may be done to evaluate blood flow
• Management:

  • Depends on underlying cause
  • If carotid artery disease =
  • Management of underlying vascular risk factors
  • Antiplatelet therapy with aspirin
  • Carotid stenting
  • Carotid endarterectomy