VEP and ERG

Visually Evoked Potential (VEP)

This test measures the electrical activity in the visual system.  When light enters your eye, it is converted to a electrical signal at the retina, which travels through the optic nerve to the visual cortex in the brain.  Using VEP, we can determine the strength of this signal as well as how long it takes to get there.  This provides valuable information in cases where compromised neurological function is the cause of the vision problem, such as amblyopia (lazy eye,) traumatic brain injury, glaucoma, multiple sclerosis, etc.  It can also be useful for getting objective measurements of visual function in non-verbal patients (e.g. young children or the devel0pmentally disabled.)

Electroretinogram (ERG)

This test measures the electrical activity of the retina, the part of the eye that detects light and converts it into electrical signals for the brain.  This test is especially useful in cases where retinal function is reduced but is not yet visible in standard retinal exam, such as genetic disorders like Stargardt’s disease or retinal toxicity from drugs like hydroxychloroquine.  It can also be useful for getting an objective measurement of retinal function in more common conditions like macular degeneration or diabetic retinopathy.