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e·lec·tro·ret·i·no·gram (ERG),

A record of the retinal action currents produced in the retina by an adequate light stimulus.
[electro- + retina + G. gramma, something written]


(ERG) (ĕ-lek'trō-ret'i-nō-gram)
A record of the retinal action currents produced in the retina by an adequate light stimulus.
[electro- + retina + G. gramma, something written]


A recording of the summation of the electric changes occurring in the retina under different conditions, such as exposure to flashes of bright light. The ERG is of value in the diagnosis of some uncommon conditions affecting the RODS or the CONES.

electroretinogram (ERG)

Recording of mass electrical response of the retina when it is stimulated by light. It is recorded by placing an electrode in contact with the cornea (often with the aid of a contact lens) or around the eye under the eyelid. A second electrode is placed either on the forehead or the face. The response is complex as many cells of various types contribute to it and varies according to whether the eye is dark or light adapted, the colour of the stimulus, the health of the retina, etc. The curve consists of two major components: a negative a-wave and a positive b-wave. The a-wave originates in the photoreceptors while the b-wave originates in the bipolar and Mueller cells. Both waves also have a photopic and a scotopic component.


the record obtained by electroretinography; abbreviated ERG.
References in periodicals archive ?
Abnormal electroretinogram in cocaine dependent patients: Relationship to craving.
The push-pull action of dopamine The push-pull action of dopamine on spatial tunning of the monkey retina: The effects of dopaminergic deficiency and selective D1 and D2 receptor ligands on the pattern electroretinogram.
The electroretinogram (ERG) is a noninvasive physiologic technique for recording electrical potentials from the retina in response to flashes of light.
We will also review the line of research focusing on the visual system, particularly involving the electroretinogram since it appears to be a cost-effective peripheral marker of dopamine dysfunction among cocaine-dependent patients.
The patients had electroretinograms, which are sophisticated, objective tests of visual function, at six months and at one year after enrolling in the study.
The team then used electroretinograms to measure visual function and found a significant loss in visual function.
In one study of 16 patients in an ophthalmologic clinic, electroretinograms showed significantly more rapid dark adaptation in those given the active extract than in those given placebo (Minerva Oftalmol.
1) Additionally, those with ASD tend to have abnormal electroretinograms, weak visual evoked potentials and atypical optokinetic nystagmus.
and his colleagues looked at electroretinograms -- tracings of retinal electrical activity that resemble the electrocardiograms used to measure heart functions -- recorded from retinal tissue they had transplanted into rats.
At the annual meeting of the Association for Research in Vision and Ophthalmology in May, Collier showed electroretinograms indicating that the transplanted cells, like normal photoreceptors, conduct waves of electrical potentials in response to light.
In a relaxed and easy-going manner, the video explains to a child who may have to undergo the assessment, how electrodes are attached and what they will look at and do while a clinician records electroretinograms, visual evoked potentials and electro-oculograms.