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Visual Evoked Potential Test

(VEP)

En Español (Spanish Version)

Definition | Reasons for Test | Possible Complications | What to Expect | Call Your Doctor

Definition

A visual evoked potential test (VEP) is used to look for problems in the brain that affect vision. A machine records brain waves related to the nerves that make up the visual pathway. This test can evaluate a large part of the brain.

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Copyright © Nucleus Medical Media, Inc.

Reasons for Test

This test is often used to:

  • Diagnose and follow multiple sclerosis (MS)
  • Test vision in children and adults who are unable to read eye charts

There are many symptoms that might lead your doctor to order a VEP. You may be having double vision, blurred vision, or loss of part or all of your vision.

Possible Complications

There are no major complications associated with this procedure.

What to Expect

You will be given instructions to prepare for the test, such as:

  • Wash your hair. Avoid hair chemicals (eg, hair sprays, gels).
  • Get a good night’s sleep.
  • Bring your corrective eyewear.

Wires will be attached to your scalp with adhesive. A patch will be placed over one eye. You will watch a screen with your other eye. The process is then repeated with the opposite eye covered.

The wires will be removed from your head.

You will be able to leave after the test is done.

About 45 minutes

No

Your doctor will discuss the results with you and any further treatment that may be needed.

Call Your Doctor

Call your doctor if you have any concerns.

In case of an emergency, GET MEDICAL CARE RIGHT AWAY.

RESOURCES:

National Eye Institute

http://www.nei.nih.gov/

National Multiple Sclerosis Society

http://www.nationalmssociety.org/

CANADIAN RESOURCES:

Canadian Association of Optometrists

http://www.opto.ca/en/index.html

Canadian Ophthalmological Society

http://www.eyesite.ca/

References:

Evoked potential studies. St. John's Mercy Healthcare website. Available at: http://www.stjohnsmercy.org/healthinfo/test/neuro/TP014.asp. Accessed September 8, 2005.

Merck Medicus website. Available at: http://www.merckmedicus.com/pp/us/hcp/thcp_raj_content.jsp?pg=/ppdocs/us/hcp/content/raj/chapters/raj-ch-026-s003.htm. Accessed September 8, 2005.

Last reviewed [Under Medical Review] by Eric L. Berman, MD

Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.