Diopsys® NOVA VEP / ERG / Enfant Vision Testing

The Diopsys® NOVA VEP / ERG / Enfant Vision Testing System is a non-invasive medical device used to help your eye doctor objectively measure the function of the entire visual pathway from the lens of the eye to the visual cortex of the brain. The test is painless and does not require dilation or sedation. The Diopsys® NOVA Systems are the only objective visual testing devices designed for the eye care professional’s office capable of evaluating the entire visual pathway available today.

How it works: After positioning three sensory pads on the patients head, an operator initiates the test. A series of black and white patterns that appear to “flip” quickly over and over again is presented to the patient on a computer screen. The eye specialist may vary the pattern size, frequency, contrast, time, and eye tested. The results may then be displayed to generate a profile for each eye (displaying responses to several size stimuli), or compare studies to assess therapy (patching, drops, lenses, prisms, and other modalities).

Who are we testing and what are we testing for?

VEP: Used for testing patients following a neurological event such as a traumatic brain injury, stroke, or a degenerative process such as multiple sclerosis in order to help the doctor detect visual deficits such as optic nerve disorders, amblyopia and other neuro-visual disorders. See this brochure for more information.

ERG: Used for testing patients who are at risk for macular disease, glaucoma and other retinal issues. See this brochure for more information.

Enfant: The Enfant® VEP vision test is an objective method to evaluate a child’s entire visual pathway including and beyond structural and refractive errors to help detect visual deficits such as visual asymmetries caused by refractive errors, optic nerve disorders, and neuro-visual dysfunction from conditions like amblyopia. See this brochure for more information.

General Information

What is a Diopsys Vision Test?

It is a painless, safe, non-invasive vision test to objectively measure neurological responses of the entire visual pathway using visual evoked potential (VEP) technology. It is much more than a common vision test.

How should I prepare for the test?

All medications should be taken as usual unless otherwise directed by the doctor. Hair should be clean, dry, and free of any gels, sprays, or oils.

It is important that you feel relaxed and comfortable so the test results are accurate. For young children it may be helpful to bring a favorite item such as a blanket, pacifier, or toy that will make them feel more comfortable.

How is the test done?

The technician will attach three small sensory pads to your head using a washable gel material. You will be seated in front of a screen and asked to stare at the center. The screen will display different size patterns that quickly reverse. One eye may be covered while the other eye is tested. A computer records your response. The test will take between 5 and 30 minutes depending on what tests your doctor orders.

What else do I need to know?

You must sit still during the test. Relaxation is an important part of the test.

What can I expect after the test?

After the test the technician will remove the sensory pads and use a small amount of water to remove any gel residue. The test results will be given to your doctor.

Eye and Vision Disorders

What is glaucoma? What causes glaucoma?

According to the Glaucoma Research Foundation, glaucoma is a group of eye diseases that gradually steal sight without warning. In the early stages of the disease, there may be no symptoms. Experts estimate that half of the people affected by glaucoma may not know they have it.

Vision loss is caused by damage to the optic nerve. This nerve acts like an electric cable with over a million wires. It is responsible for carrying images from the eye to the brain. There is no cure for glaucoma yet. However, medication or surgery can slow or prevent further vision loss. Early detection is vital to stopping the progress of the disease.

Signs and Symptoms of Glaucoma

Depending on the type of glaucoma you have, you may experience a gradual loss of peripheral vision, tunnel vision, halos around lights, blurred vision, severe eye pain, sudden onset of visual disturbance, often in low light, and reddening of the eye.

Do not wait to visit your eye doctor until you have a problem because in the early stages of the disease, there may be no symptoms. Regular eye exams are the key to detecting glaucoma early enough for successful preventive treatment.

What is diabetic retinopathy?

The National Eye Institute defines diabetic retinopathy as an eye disease that causes changes in the blood vessels of the retina that results as a complication of diabetes. In some people with diabetic retinopathy, blood vessels may swell and leak fluid. In other people, abnormal new blood vessels grow on the surface of the retina.

In the early stages of the disease, there may be no symptoms; but, over time, diabetic retinopathy can get worse and cause vision loss. Diabetic retinopathy usually affects both eyes.

Signs and Symptoms of Diabetic Retinopathy

Blurred vision may occur when the macula-the part of the retina that provides sharp central vision-swells from leaking fluid. This condition is called macular edema. If new blood vessels grow on the surface of the retina, they can bleed into the eye and block vision. You may see a few specks of blood, or spots, “floating” in your vision.

Do not wait to visit your eye doctor until you have a problem because there are often no symptoms in the early stages of the disease. Be sure to have a comprehensive dilated eye exam at least once a year.

What is multiple sclerosis (MS)?

According to the National Multiple Sclerosis Society, MS is a chronic, unpredictable disease of the central nervous system (the brain, optic nerves, and spinal cord). It is thought to be an autoimmune disorder. This means the immune system incorrectly attacks the person’s healthy tissue.

Signs and Symptoms of Multiple Sclerosis

Symptoms of MS are unpredictable, vary from person to person, and from time to time in the same person. MS can cause blurred vision, loss of balance, poor coordination, slurred speech, tremors, numbness, extreme fatigue, problems with memory and concentration, paralysis, and blindness and more. These problems may be permanent or may come and go.

Most people are diagnosed between the ages of 20 and 50, although individuals as young as 2 and as old as 75 have developed it. Multiple sclerosis is not considered a fatal disease as the vast majority of people with it live a normal life-span. But they may struggle to live as productively as they desire, often facing increasing limitations.

What is traumatic brain injury (TBI)?

The National Institute of Neurological Disorders and Stroke say traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain. TBI can result when the head suddenly and violently hits an object, or when an object pierces the skull and enters brain tissue.

Signs and Symptoms of Traumatic Brain Injury

Symptoms of TBI can be mild, moderate, or severe, depending on the extent of the damage to the brain. A person with mild TBI may remain conscious or may experience a loss of consciousness for a few seconds or minutes. Other symptoms of mild TBI include headache, confusion, lightheadedness, dizziness, blurred vision or tired eyes, ringing in the ears, bad taste in the mouth, fatigue or lethargy, a change in sleep patterns, behavioral or mood changes, and trouble with memory, concentration, attention, or thinking. A person with a moderate or severe TBI may show these same symptoms, but may also have a headache that gets worse or does not go away, repeated vomiting or nausea, convulsions or seizures, an inability to awaken from sleep, dilation of one or both pupils of the eyes, slurred speech, weakness or numbness in the extremities, loss of coordination, and increased confusion, restlessness, or agitation.