John G. McHenry, M.D., M.P.H., P.L.L.C.

Appointments
214.753.8500

Services & Procedures

Visual Evoked Potentials

Appointment Request

In many patients it is difficult to determine the cause of visual loss.  These patients may require electrophysiology tests.  One such test is a visual evoked potential.  We have two visual evoked potential machines.  Both test the conduction of the optic nerves to the brain.  You will be asked to look into a screen at a pattern of light.  There will be electrodes placed around the eye and brain which will measure the conduction of impulses back to the occipital lobe.  The impulses are then recorded and added together to get a wave form.  We then measure the amplitude of the response and how quick the response occurs.  This can tell us whether there is optic nerve disease and help us in your diagnosis.  Then we can look at this test over the long term to see if there is improvement with treatment.  This test takes only a few minutes to perform and is noninvasive.