What Is an Electroretinogram?

For a composite electrical reaction. The method of guidance is to contact a guide electrode with the cornea and place another reference electrode with a larger area on the forehead. When the retina is stimulated with light, a series of electrical changes can be recorded on the oscilloscope, that is, the electroretinogram.

Electroretinogram

Right!

For a composite electrical reaction. The method of guidance is to contact a guide electrode with the cornea and place another reference electrode with a larger area on the forehead. When the retina is stimulated with light, a series of electrical changes can be recorded on the oscilloscope, that is, the electroretinogram.

Electroretinogram (ERG)

The ERG can be divided into several parts. A typical ERG is shown by the thick line in the figure. Under light stimulation, there is a small negative wave (the cornea is negative), called a wave, and then a positive (corneal is positive) b wave appears. If the stimulus intensity is large, after the b wave, there is a positive wave that rises slowly (the cornea is positive), which is called the c wave. At the end of the light stimulation, there will also be a positive upward protrusion of the cornea, called the d-wave. According to analysis, the a wave is mainly derived from the sensory potential of photoreceptor cells; the b wave has a large amplitude, which is mainly related to the activity of bipolar cells; the c wave rises slowly and persistently, which may be related to the normal function of the pigment epithelial cell layer; the d wave is A light withdrawal response.