Transient visual loss






Introduction


Transient visual loss can be caused by disease of the:



  • •

    eye


  • •

    optic nerve


  • •

    orbit


  • •

    brain


  • •

    neck


  • •

    heart

A careful history and examination can often localize the disease. The most critical distinction is whether transient visual loss is monocular or binocular but this is often very difficult to establish on history as patients may believe that because they have transiently lost vision to the left or right, the loss has been in the left or right eye!


Overall, the most common cause of monocular transient visual loss seen by ophthalmologists is amaurosis fugax due to carotid stenosis; the most common cause of transient binocular visual disturbance is migraine. However, there are many other causes, including giant cell arteritis (GCA), compressive optic nerve tumor and papilledema.


Non-migraine transient visual loss is often the first warning sign of serious systemic vascular disease. Rather than just reassuring the patient that “there is nothing wrong with your eyes”, it is important to refer or investigate them appropriately. A few minutes of your time may add many years to their life.


As ophthalmologists, we all need to know the following four things about transient visual loss:



  • 1.

    How to make a clinical diagnosis of amaurosis fugax and how patients with this symptom should be investigated (p. 156).


  • 2.

    How to make a clinical diagnosis of the visual prodrome of migraine (with or without headache) (p. 157).


  • 3.

    How to make a clinical diagnosis of vertebrobasilar insufficiency (VBI) and how patients with this condition should be investigated (p. 158).


  • 4.

    And what to do for all other patients with transient visual loss. We recommend that these patients be referred to a neuro-ophthalmologist for further assessment.



Monocular transient visual loss


Transient visual loss in one eye can be caused by disease in the:



  • •

    eye: transient angle-closure glaucoma, tear film disturbance, incipient retinal vascular occlusion, retinal vasospasm (previously called “ocular migraine”)


  • •

    optic nerve: compressive orbital tumor, Uhthoff phenomenon, GCA


  • •

    brain: papilledema, pituitary tumor compressing one intracranial optic nerve


  • •

    neck: amaurosis fugax (transient monocular embolic visual loss) or ocular ischemic syndrome due to carotid artery atherosclerosis or internal carotid dissecting aneurysm


  • •

    heart: valve disease releasing emboli that cause amaurosis fugax



Binocular transient visual loss


Transient visual loss in both eyes can be caused by disease in:



  • •

    both eyes or optic nerves at the same time (rare)


  • •

    the brain: migraine (with or without headache), transient visual obscurations (TVOs) due to papilledema, bilateral optic nerve or chiasmal compression by pituitary tumor


  • •

    the neck or heart: transient homonymous or global visual field loss due to embolism in the carotid or vertebrobasilar arterial systems, VBI due to atherosclerosis or dissecting aneurysm, postural hypotension/presyncope





Examination checklist


Transient visual loss


Have you asked about, and looked for, all the following key features?


History




  • □

    ophthalmic symptoms?


  • □

    the episode/s of transient visual loss



    • –

      one or both eyes affected? How do you know? Did you cover one eye and then the other to see if one or both eyes were affected?


    • –

      activities at onset/precipitating factors?


    • –

      speed of onset?


    • –

      exact nature of visual symptoms? Positive phenomena (e.g. flashing lights, zig-zag lines), negative phenomena (blacking or blanking out) or both?


    • –

      development over time?


    • –

      how long did it last?


    • –

      speed and nature of recovery of vision?


    • –

      any residual symptoms or is everything back to normal now?



  • □

    any neurologic symptoms before, during or after the episode?



    • –

      any headache? If so, describe nature; did it occur before, during or after the visual loss?


    • –

      nausea, vomiting, photophobia or sonophobia?


    • –

      transient numbness, weakness, collapse, problems walking or talking during the episode of blurred vision?


    • –

      if neurologic symptoms present, have they completely resolved?



  • □

    any other ophthalmic symptoms?



    • –

      haloes around lights and/or red painful eye during episode: suspect angle-closure glaucoma


    • –

      transient diplopia?



  • □

    previous medical and surgical history



    • –

      true migraine? (caution: some patients call every headache “migraine”)


    • –

      somnambulism in childhood, cyclic vomiting in childhood or previous or current motion sickness? (all migraine equivalents)


    • –

      transient ischemic attacks or stroke?


    • –

      atherosclerotic risk factors?


    • –

      recent neck trauma, car accident, chiropractic manipulation, roller-coaster ride? (internal carotid artery [ICA] dissection)



  • □

    social history: smoker?


  • □

    family history of true migraine? (caution: some patients call every headache “migraine”)


  • □

    if patient over 50: symptoms of giant cell arteritis (GCA)?


  • □

    system review questions



    • –

      neck or face pain? (ICA dissection)


    • –

      any clues to the cause anywhere in the body?




Examination




  • □

    visual acuity testing


  • □

    color vision testing


  • □

    visual field testing to confrontation


  • □

    eye movement testing


  • □

    pupils



    • –

      relative afferent pupillary defect (RAPD)?


    • –

      anisocoria?



  • □

    eyelids: ptosis?


  • □

    orbits: proptosis, injection, chemosis?


  • □

    decreased corneal and/or facial sensation to light touch?


  • □

    if patient over 50: palpate temporal arteries


  • □

    measure blood pressure in all cases


  • □

    carotid bruit audible with stethoscope?


  • □

    full neurologic examination: in all cases of unexplained transient visual loss



Plus: perform perimetry:




  • □

    IN ALL CASES





Management flowchart


Transient visual loss







Clinical diagnostic criteria for Amaurosis fugax

(transient monocular embolic visual loss)


The patient must have ALL of the following:


History




  • •

    age over 50 and vasculopathic risk factors


  • •

    sudden onset of severe visual loss in one eye (usually at least several minutes, most often >5 minutes)


  • •

    visual loss over part or all of the monocular visual field (“a curtain came over my vision”)


  • •

    visual loss completely resolves within 1 hour (usually resolves within 10 minutes)


  • •

    normal vision in the other eye throughout


  • •

    no other neurologic symptoms


  • •

    no neck pain, no history of neck injury (possible carotid dissecting aneurysm)


  • •

    no symptoms of GCA ( p. 46 )



Examination




  • •

    normal ocular examination in both eyes, with the exception that retinal emboli may or may not be seen in one or both eyes


  • •

    normal neuro-ophthalmic examination; specifically no Horner syndrome (possible carotid dissecting aneurysm)


  • •

    no signs of GCA ( p. 46 )



Perimetry




  • •

    normal in both eyes



IF THE PATIENT MEETS ALL THESE CRITERIA, SEE P. 162 FOR INVESTIGATIONS AND MANAGEMENT.



Clinical diagnostic criteria for Visual prodrome of migraine


The patient must have ALL of the following:


History




  • •

    known history of true migraine headaches or migraine equivalents (e.g. motion sickness, somnambulism, cyclic vomiting) commencing before age 40


  • •

    history of expanding scintillating scotoma



    • –

      area of blurred vision in both eyes (seen with both eyes open)


    • –

      begins as a small area of blurred vision that then expands slowly over 10–30 minutes before resolving; this may or may not be hemianopic


    • –

      the scotoma is surrounded by one or more of the following: zig-zags, flashing or sparkling lights or wavy/“watery” vision



  • •

    vision returns completely to normal in both eyes


  • •

    if headache is present, it begins after the start of visual symptoms (headache starting before or at the same time as the onset of visual symptoms could be a mass lesion)


  • •

    the visual loss may or may not be followed by a transient period with one or more of: nausea, vomiting, photophobia, sonophobia or malaise


  • •

    no other neurologic symptoms (migraine can cause other neurologic symptoms but the presence of other symptoms indicates the patient should be seen by a neurologist)


  • •

    (if older than 50) no symptoms of GCA ( p. 46 )



Examination




  • •

    normal ocular examination in both eyes


  • •

    normal neuro-ophthalmic examination


  • •

    (if older than 50) no signs of GCA ( p. 46 )



Perimetry




  • •

    normal in both eyes



IF THE PATIENT MEETS ALL THESE CRITERIA, SEE P. 166 FOR INVESTIGATIONS AND MANAGEMENT.



Clinical diagnostic criteria for Vertebrobasilar insufficiency


The patient must have ALL of the following:


History




  • •

    age over 50 and vasculopathic risk factors


  • •

    sudden onset of visual loss in both eyes; this may or may not be hemianopic


  • •

    visual loss completely resolves within 1 hour (more often within minutes)


  • •

    often one or more other transient neurologic symptoms are present (lasting minutes usually, then completely resolving)



    • –

      loss of balance/vertigo


    • –

      problems walking, talking or swallowing


    • –

      numbness around the mouth


    • –

      numbness or weakness on one or both sides of the body


    • –

      collapse



  • •

    no neck pain, no history of neck injury (possible vertebrobasilar dissecting aneurysm)


  • •

    no symptoms of GCA ( p. 46 )



Examination




  • •

    normal ocular examination in both eyes


  • •

    normal neuro-ophthalmic examination


  • •

    no signs of GCA ( p. 46 )



Perimetry




  • •

    normal in both eyes



IF THE PATIENT MEETS ALL THESE CRITERIA, SEE P. 168 FOR INVESTIGATIONS AND MANAGEMENT.

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Related posts:

  1. Abnormal eye movements without visual symptoms
  2. Unexplained eye pain, orbital pain or headache
  3. Swollen disc/s, normal vision: (Note: for swollen disc/s with blurred vision or field loss, see)
  4. Neuro-ophthalmic history and examination

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Jun 25, 2019 | Posted by in OPHTHALMOLOGY | Comments Off on Transient visual loss

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