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Transient Monocular Blindness

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Transient Monocular Blindness, Amaurosis Fugax

  • See Also
  1. Temporal Arteritis
  2. Acute Vision Loss
  3. Acute Retinal Ischemia
  • Definition
  1. Transient Monocular Blindness (Amaurosis Fugax)
    1. Transient painless unilateral Vision Loss
  • Symptoms
  1. Acute Vision Loss ("Fleeting blindness")
    1. Sudden painless, unilateral blindness
    2. Vision returns to normal in 1-10 minutes
    3. "Shade or curtain" descends over affected eye
  • Causes
  1. Transient Central Retinal Artery Occlusion (embolism)
  2. Optic Nerve ischemia (Giant Cell Arteritis or Temporal Arteritis)
    1. May be associated with temporal Headache, Jaw Claudication or Polymyalgia Rheumatica history
  • Labs
  1. Age over 50 years old (Temporal Arteritis risk)
    1. Erythrocyte Sedimentation Rate (ESR)
    2. C-Reactive Protein (CRP)
  • Differential Diagnosis
  1. See Acute Vision Loss
  2. See Acute Retinal Ischemia
  • Precautions
  1. Transient Vision Loss may progress to permanent Vision Loss (or even bilateral Vision Loss) within 1 week
  • Management
  1. Urgent ophthalmology Consultation within 24 hours
  2. Giant Cell Arteritis suspected (e.g. ESR/CRP increased)
    1. See Giant Cell Arteritis
    2. Consult general surgery for temporal artery biopsy
    3. Start high dose Corticosteroids
      1. Prednisone 80-100 mg orally daily OR
      2. Methylprednisolone 250 mg every 6 hours for 3 days, then transition to oral
  3. Optic Nerve ischemia from embolism suspected
    1. Evaluate as Transient Ischemic Attack
    2. Obtain MRI Brain (with diffusion weighted imaging)
    3. Evaluate carotid arteries (e.g. carotid Ultrasound, or CT or MR Angiogram Head and Neck)
    4. Electrocardiogram (evaluate for Atrial Fibrillation)
    5. Zio monitor or Holter Monitor (or telemetry if on hospital observation)
    6. Echocardiogram
  • References
  1. Hartmann (2016) Crit Dec Emerg Med 30(6): 3-11
  2. Biousse (2018) Ophthalmology 125:1597-607 [PubMed]