Diagnostic Tests

Electrophysiological Tests

Electroretinography (ERG), pattern electroretinography (Pattern ERG), multifocal electroretinography (Multifocal ERG), electro-oculography (EOG) and visual evoked potential (VEP) are practical electrophysiological tests which are often used.  

The tests give valuable information about the visual pathways of the optic nerve and brain, macula and retina. This information helps in diagnosis of the disease and defining treatment. Evaluation of the retina and visula pathways gives the opthalmologist objective information.

Figure 1. Electrophysiological examinations including electroretinogram (ERG) and visual evoked potentials (VEP) are available at our hospital.

In some tests the pupil is enlarged with drops and electrodes are placed on the eye, around the eye, on the forehead and the hairline. The tests are usually conducted in a darkened room. The tests are completely painless and there are no side effects. In this method, the electrical response is measured and recorded on special computer screens. Approximately 2 hours are required for the application of these tests. This is a diagnostic method which requires, patience, experience, knowledge and substantial experience for the evaluation. It is used in the diagnosis and monitoring of hereditary retina diseases such as retinitis pigmentosa (night blindness), hereditary macular dystrophy, Stargart disease and Best vitelliformdystrophy, in toxic retinopathies and in neuro-opthalmological diseases.