Electroretinography
| Electroretinography | |
|---|---|
 Maximal response ERG waveform from a dark adapted eye. | |
| ICD-9-CM | 95.21 |
| MeSH | D004596 |
Electroretinography measures the electrical responses of various cell types in the
If a dim flash ERG is performed on a dark-adapted eye, the response is primarily from the
Diagnostics
Clinically used mainly by ophthalmologists the electroretinogram (ERG) is used for the diagnosis of various retinal diseases.[2]
Inherited retinal degenerations in which the ERG can be useful include:[citation needed]
- Retinitis pigmentosa and related hereditary degenerations
- Retinitis punctata albescens
- Leber's congenital amaurosis
- Choroideremia
- Gyrate atrophy of the retina and choroid
- Goldman-Favre syndrome
- bipolar cellregion.
- X-linked juvenile retinoschisis
- Achromatopsia
- Cone dystrophy
- Disorders mimicking retinitis pigmentosa
- Usher syndrome
Other ocular disorders in which the standard ERG provides useful information include:
- Diabetic retinopathy[3][4][5]
- Other ischemic retinopathies including central retinal vein occlusion (CRVO),[6] branch vein occlusion (BVO), and sickle cell retinopathy
- Toxic retinopathies, including those caused by Plaquenil and Vigabatrin. The ERG is also used to monitor retinal toxicity in many drug trials.
- Autoimmune retinopathies such as cancer associated retinopathy (CAR), melanoma associated retinopathy (MAR), and acute zonal occult outer retinopathy (AZOOR)
- Retinal detachment
- Assessment of retinal function after trauma, especially in vitreous hemorrhage, dense cataracts, and other conditions where the fundus cannot be visualized.
The ERG is also used extensively in eye research, as it provides information about the function of the retina that is not otherwise available.
Other ERG tests, such as the photopic negative response (PhNR) and pattern ERG (PERG) may be useful in assessing retinal ganglion cell function in diseases like glaucoma.
The multifocal ERG is used to record separate responses for different retinal locations.
The international body concerned with the clinical use and standardization of the ERG, EOG, and VEP is the International Society for the Clinical Electrophysiology of Vision (ISCEV).[7]
Other uses
In addition to its clinical diagnostic purpose, the ERG can be used during the course of drug development and in clinical trials for testing ocular safety and efficacy of new or existing drugs and treatment modalities.[8]
A 2013 study[9] by Nasser et al. found that the retinal dopaminergic response to eating a brownie is equivalent in magnitude to the response to a 20 mg dose of methylphenidate, which implies that the activity of dopamine neurons in the retina reflects brain dopaminergic activity. The study concludes that, if verified by further research, "ERG could provide the neurotransmitter specificity of PET at a much lower cost".
The ERG has been shown to differ in people with schizophrenia[10] and may be useful in helping to differentiate schizophrenia and bipolar disorder.[11]
History
ERG was one of the earliest recorded biological potential. The first known ERG was recorded by the Swedish physiologist
See also
- Electrooculography
- Visual evoked potential
References
- ^ Perlman, Ido. "The Electroretinogram: ERG by Ido Perlman". Webvision at University of Utah. Archived from the original on 2015-12-28.
- ^ Electroretinography, U.S. National Library of Medicine, 11 April 2005 (accessed 19 January 2007)
- PMID 26803474.
- S2CID 207934593.
- PMID 32908803.
- PMID 30550616.
- ^ ISCEV Website
- S2CID 3154513.
- PMID 23784899.
- S2CID 13663072.
- S2CID 195699284.
- ^ a b c d e "Electroretinogram - EyeWiki". eyewiki.aao.org.
- ^ ISBN 978-0-674-76680-8.
