Transient Monocular Visual Loss

  • Abrupt temporary loss of vision in one eye that lasts from seconds to hours
  • Results from reduced blood flow to affected eye
  • Causes are systemic hypotension, embolism originating in stenotic cervical carotid artery, atrial fibrillation, cardiac valve or mural thrombus, impending retinal or optic nerve stroke, vasospasm of retinal arterioles, hyperviscosity/hypercoagulable states, and optic disc edema, including papilledema
  • Blank, fuzzy, dark, bright, or flickering area covering all or part of visual field of one eye, BUT...
  • Patients who insist that visual loss affected only ONE eye may actually have suffered loss to both hemifields ("homonymous hemianopia"), especially if they report that "one side of vision was blank", or that they could not read normally despite having good vision in "unaffected" eye
  • Patients who describe "curtain coming down" or "curtain coming up" have definitely had reduced blood flow to ONE eye
  • Repeated visual loss lasting no more than seconds, especially if provoked by sitting or standing, suggests papilledema
  • Mucus debris in tear film can disturb vision temporarily
  • Corneal edema from endothelial malfunction or intermittent intraocular pressure elevation can do this, BUT...
  • Neither condition causes ABRUPT visual loss
  • All patients should undergo ophthalmologic examination to look for papilledema, retinal platelet-fibrin or calcific embolus, retinal or optic nerve ischemia
  • Even if ophthalmologic exam is negative, evaluation for underlying causes must occur
  • Ocular or brain stroke may occur if preventive measures are not taken
  • Papilledema is sign of increased intracranial pressure with life-threatening causes
  • Papilledema is threat to vision if increased intracranial pressure is neglected