Standard electro-retinogram. The ERG is an examination or diagnostic means that results in a record of an electrical potential generated by the entire retina in response to a short flash of light. It is recorded by placing electrodes in the form of contact lenses or a nylon thread. silver coated. The equipment used allows selecting the stimulus for the cones and rods, alternating the intensity of the light. The last stimulus consists of a high-frequency flash (flicker) that evaluates the activity of the cones.

Multifocal electro-retinogram. The mfERG is a test or diagnostic tool that reflects electrical activity in isolated areas of the retina (represented by rings or quadrants) in response to several simultaneous light stimuli in the form of hexagons. It is recorded by placing electrodes in the form of silver-coated nylon threads.

Electro-retinogram in Pattern. The P-ERG is a test or diagnostic tool that reflects the functional activity of the ganglion cells and helps us to differentiate whether a functional disorder comes from the macula or the optic nerve. A stimulus in the form of a pattern of 16 frames (48 min) is used, thus capturing the response by placing electrodes in the form of silver-coated nylon threads.