VEP / ERG

What is the VEP?

Visual evoked potential (VEP) directly measures the electrical activity in the vision system.     When light from an image enters our eye, it is converted into electricity at the retina and travels through the optic nerve and other pathways to the part of our brain that processes vision, the visual cortex.  The VEP will measure the strength of the signal reaching your visual cortex and how fast it gets there.

The VEP technology helps us determine how your eyes communicate with your brain in a way that no other instrument or vision test can.

VEP testing is a painless, non-invasive vision test that objectively measures the function of the entire visual pathway from the eyes to the visual center of the brain. 

VEP has been demonstrated to aid in the diagnosis and treatment of many disorders including amblyopia, brain injury, stroke, glaucoma, multiple sclerosis, and other vision-related issues.  The purpose of this series of tests is to provide comprehensive diagnostic information to better plan your treatment and monitor the results.

Vision disorders are often difficult to diagnose, as many current vision testing instruments used in an eye doctors office do not measure vision beyond the eye.  Also, many standard vision tests require a patient to give a verbal response, but if the patient is an infant or has trouble communicating, these tests may not always provide the doctor with the most accurate information.

By using Visual Evoked Potential technology, we can measure the entire vision system, from the front of the eye to the visual cortex of the brain, without the patient having to say a word.

The Diopsys® NOVA-ERG Vision Testing System is an office-based pattern electroretinography (ERG) module – a part of the Diopsys® NOVA suite of tests. Pattern electroretinography can help doctors gain objective, functional information about the performance of the inner retinal cells of the eye, especially in the macula.

No verbal response or “button pushing” required, providing objective results.

Report contains quantitative information formatted to facilitate physician test interpretation and patient management.

Documents the results of practitioner intervention for tracking patients’ response.

The Diopsys® NOVA-ERG conforms to the standards of the International Society for Clinical Electrophysiology of Vision (ISCEV)

The Diopsys® NOVA Vision Testing System provides your doctor with painless, non-invasive vision tests that utilize electrophysiological technology, including Visual Evoked Potential (VEP) and pattern 

Electroretinography (ERG).

The purpose of these tests is to provide comprehensive information to assist your doctor in better planning your treatment (if needed) and monitoring the results.

Visual Evoked Potential (VEP)

VEP measures the electrical activity in the vision system. When light from an image enters your eye, it is converted into electrical energy at the retina and travels through the optic nerve to the visual cortex of the brain which processes vision. The Diopsys® NOVA-VEP test measures the strength of the signal reaching your visual cortex and how fast it gets there.

The VEP technology in the Diopsys® NOVA device helps determine how your eyes communicate with your brain in a way that no other instrument or vision test can.

How the Test is Done

First the technician will prepare your skin to be clean, dry, and free of any lotions or oils so the sensory pads can be placed on your head. 

After positioning the sensory pads, the technician starts the test. He or she may ask that you cover one eye at a time to record each eye’s response independently. Once the test begins, you will see a series of black and white patterns that appear to “flip” quickly over and over again on a computer screen. It is simply a matter of looking at the pattern for the duration of the test. The computer will capture the information and produce a report for the doctor’s interpretation of the results.

Preparing for your Test

It is best for your hair and face to be clean, dry, and free of any gels, sprays or oils.

Pattern Electroretinography (ERG)

ERG measures the function of your retina – the light-sensitive layer at the back of your eye. When light from an image enters the eye, it is converted into electrical energy by specialized cells in the retina. These cells send electrical impulses through the optic nerve to the brain where the image is processed. The Diopsys® NOVA-ERG test records how well the cells of the retina are conveying electrical impulses within the eye.

ERG results have been demonstrated to aid in the diagnosis and treatment planning of many vision disorders.