Eye Library / Diagnostic Tests / Electrophysiology Tests

Electrophysiology Tests : reflect retinal, optic nerve and visual pathway function and provide important information for ocular disease diagnosis and treatment. Currently, It is regarded as the only objective way to determine the function of the retina and visual pathway.

The tests include electroretinogram (ERG) to assesses the aggregate response of the retina, visual evoked potential (VEP), a response evoked from the visual cortex, and electro-oculogram (EOG).

During all the tests, we will attach two to five electrodes to the skin around the eye, on the ear lobe or on the head. These electrodes are non-invasive, painless, and will measure electric responses. During and ERG test, First the health care provider places numbing drops into your eyes, so you do not feel pain during the test, then the pupil is dilated and a special corneal contact lens electrode is placed. The patient will then be dark-adapted in dark room for approximately 30-40 minutes. A light flashes, and the electrical response travels from the electrode to a TV-like screen, where it can be viewed and recorded. No special preparation is necessary for this test. The probes that rest on your eye may feel like an eyelash. The test takes about one hour to perform.

Both hereditary and acquired disorders of the retina can be evaluated with this test. It is also useful in determining if retinal surgery is recommended.