Electroretinography (ERG) is a major diagnostic and reserarch method in ophthalmology. It involves recording, measuring and analyzing electrical responses of various cell types in the retina of the eye, including the photoreceptors (rods and cones), inner retinal cells (bipolar and amacrine cells), and the ganglion cells in response to photic (visual) stimuli.
Veterinary Electroretinograph is an electronic device performing Electroretinography (ERG) in animals.
To perform ERG, electrodes (such as ERG Jet) are placed on the surface of the cornea or on the skin beneath the eye (Sensor Strips) to measure retinal responses.
During a recording, the subject's eyes are exposed to standardized stimuli, and the evoked signal (response) is displayed showing the time course of the signal's amplitude (voltage). ERG signals are very faint, typically measured in microvolts or nanovolts, and therefore, require averaging of responses to multiple stimuli.
The ERG is composed of electrical potentials generated by different cell types within the retina. Various stimulus conditions (flash or pattern stimulus), with or without background light, and the colors of the stimulus and background can elicit stronger response from certain components.
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