Transient Visual Loss
What is transient vision loss?
Vision loss that is temporary (transient) is a common problem and has many potential causes. Patients with temporary vision loss often do not have any abnormalities on their eye examination, especially once the vision has returned to normal. Your doctor may need to rely on your description of the vision problem to help determine what testing needs to be performed and what the possible causes may be.
What are the possible causes of a temporary vision problem?
There are many causes of temporary vision loss:
Migraine (Figure 1)
Spasm of blood vessels to the retina (back part of the eye that senses light)
Blood flow problems to the eye, optic nerves, or brain
Swelling of the optic nerve (especially if the vision problem happens when coughing, bending over, or sneezing)
Eye surface problems, like dry eyes
Multiple sclerosis: the vision can get worse temporarily with heat or exercise (Uhthoff’s phenomenon)
Seizures (very rare)
What is the doctor looking for when examining my eyes?
The eye examination is often normal in patients with a temporary vision problem. However, a careful eye examination may reveal abnormalities that help narrow down the possible causes of a temporary vision problem. Your doctor will talk to you about any abnormalities during your examination and what they mean.
What additional testing may be performed?
In some patients, additional testing may be helpful:
Visual Field Testing
This test evaluates your side vision to determine if a spell of transient visual loss may have left a persistent abnormality. This testing can be helpful even if you feel your vision is normal, since you may not be fully aware of vision loss on the sides (periphery) of your vision.
This imaging technique involves giving a yellow dye through an IV in the arm. A camera takes a series of pictures of the dye traveling through the blood vessels in the back of the eye (retina). This allows your doctor to see abnormalities of the retinal blood vessels.
Carotid Artery Ultrasound
This test uses sound waves to image the large arteries in your neck (carotid arteries). The ultrasound looks for abnormal narrowing of these arteries, which can form clots that travel to the eye or brain.
This is a heart ultrasound that can look for any evidence of a clot or other heart abnormality that could temporarily block off a blood vessel in the head or eye and cause vision loss.
Blood testing can be helpful in some cases by looking for evidence of inflammation in the body (ESR and CRP tests) or an abnormal tendency toward blood clotting.
Computed Tomography Angiography (CTA), Magnetic Resonance Imaging or Angiography (MRI/MRA)
CTA and MRA are scans that usually involve a contrast dye injected into a vein that circulates into the arteries, at which time pictures of the blood vessels are taken, usually in the head and neck in patients with vision loss. This provides information about any blood vessels that may be blocked, narrowed, or have another abnormality that could affect vision. An MRI of the brain and/or eye sockets (orbits) may be helpful in looking for evidence of new or past strokes or other abnormalities that could be related to the vision problem (Figure 2).
What are the treatment options?
Treatment of your temporary vision problem depends on what is causing it. Some conditions aren’t dangerous and do not require any treatment. In some cases treatment may be helpful in preventing permanent visual loss or other neurologic problems. Your doctor will talk to you about what treatment is right for you.
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This information was developed collaboratively by the Patient Information Committee of the North American Neuro-Ophthalmology Society. This has been written by neuro-ophthalmologists and has been edited, updated, and peer-reviewed by multiple neuro-ophthalmologists. The views expressed in this brochure are of the contributors and not their employers or other organizations. Please note we have made every effort to ensure the content of this is correct at time of publication, but remember that information about the condition and drugs may change. Major revisions are performed on a periodic basis.
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