Electroretinography

Electroretinography, is used to measure the electrical responses of various cell types in the retina, including the light-sensitive cells(rodsand cones) and the ganglion cells. Electrodesare placed on the corneaand the skin near the eye. During a recording, the patient is watching a standardized stimulusand the resulting signal is interpreted in terms of its amplitude (voltage) and time course. Stimuli include flashes (flash ERG) and reversing checkerboard patterns (pattern ERG). Applications are predominantly in ophthalmology, where the electroretinogram (ERG) is used for the diagnosis of various retinal diseases:

• Retinitis pigmentosaand related hereditary degenerations
• Retinitis pigmentosa sine pigmento
• Retinitis punctata albescens
• Leber's congenital amaurosis
• Choroideremia
• Gyrate atrophy of the retina and choroid
• Goldman-Favre syndrome
• Congenital stationary night blindness- normal a-wave indicates normal photoreceptors; absent b-wave indicates abnormality in the bipolar cellregion.
• X-linked juvenile retinoschisis
• Achromatopsia
• Cone dystrophies
• Disorders mimicking retinitis pigmentosa

The multifocalERG is used to record separate responses for different retinal locations.

See also

• Electrooculography
• International Society for Clinical Electrophysiology of Vision
• Visual evoked potential

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It uses material from the http://en.wikipedia.org/wiki/Electroretinography Wikipedia article Electroretinography.