Visual Evoked Potential (VEP) Test
Visual evoked potentials ( VEP) are used to test the brain's occipital region for blindness or other vision problems that may occur during surgery. During a VEP test, a flashing light is used to stimulate each eye. If the patient does not react to the light, it may indicate that they are suffering from vision loss or that the signal to the brain has been delayed. While this may be a sign of a serious condition, the patient's unstable vision may simply be the result of anesthetic effects. Therefore, an experienced neural monitoring technologist is needed to determine the cause of such vision changes.
If a patient does not respond to the flashing light during the visual evoked potentials (VEP) test, and the effects of anesthetic do not seem to be interfering with the results, our neural monitoring technologists will notify the attending surgeon so that appropriate measures can be taken to further protect the patient's vision.
Types of Surgeries that Use VEP Monitoring
A visual evoked potentials (VEP) test may be used in any surgery that puts the optical nerve at risk. For instance:
- transsphenoidal pituitary tumor surgery
- frontal craniotomies for optic nerve tumors
Advantages of VEP
Visual evoked potentials can help to prevent blindness and other forms of vision loss that may occur as a result of optic nerve damage. A VEP test will be used to check the status of a patient's vision throughout the surgical procedure.
Disadvantages of VEP
Since anesthetic can affect the way a patient responds to visual evoked potentials, a VEP test may require our neural monitoring technologists to further interpret the data. Additionally, visual evoked potentials do not give functional information about monocular pathways, so even after vision loss or a change in vision has been determined, the exact cause of the damage may still be unknown.
For visual evoked potentials monitoring, contact Biotronic today. Our neural monitoring technologists have extensive experience in all areas of neurophysiologic intraoperative monitoring. Through a VEP test, we can protect the vision of patients undergoing procedures where the optic nerve is at risk.