What is ERG testing and how does it work?

About RETeval handheld ERG:

The RETeval® is a handheld visual electrophysiology device that allows your doctor to detect

functional stress in the retina and optic nerve pathways using electroretinography (ERG) and

visual evoked potential (VEP) assessments. Testing is comfortable, simple, and efficient, using

adhesive electrodes to record the electrical impulses from the back of the eye when

stimulated by a flash of light. These assessments can help your doctor detect and manage

diseases such as diabetic retinopathy, glaucoma, and inherited and acquired retinal

dystrophies.

About Electroretinography (ERG):

Your doctor is conducting an ERG test because they would like to have more comprehensive

information on the function of your retina. The retina is the layer in the back of your eye that

responds to light. When light is detected by your retina it is converted into an electrical

signal.

The RETeval® device performs an ERG test that records the speed and strength of the

electrical response of your retina when stimulated by a series of flashes of light. The signal is

collected through the Sensor Strips – little stickers located under your eye, similar to what is

used during an electrocardiogram (ECG) testing.

The device will automatically compare your results to a healthy population of patients of the

same age. It will flag any abnormalities and will help your doctor in the diagnosis and

treatment of many vision disorders.

About Visual Evoked Potential (ERG):

Your doctor is conducting a VEP test because they would like to have more comprehensive

information on the electrical activity between your eye and the visual cortex in your brain.

The visual cortex in the brain processes electrical signals sent from the retina and gives you

the sensation of vision.

A VEP sensor will be placed on the back of your head that will detect the signal sent to your

visual cortex when your retina is stimulated by a series of flashes of light.

The results will tell your doctor if there are any issues with your eyes communicating with

your brain.

How is an ERG test done?

• The technician will prepare the skin under your eyes where the Sensors Strips will be placed to be clean, dry and free of any lotions or oils. This will ensure that the sensors can detect the electrical signal generated by your retina.
• The technician may ask you to cover the non- tested eye and will place the RETeval® device in front of your eye.
• You will see a red fixation light and a series of flashes of light. Continue to look at the red light for the duration of the test. Make sure to follow the technician’s instructions.

How is a VEP test done?

• The technician will prepare the skin in the area where the sensors will be placed to be clean, dry and free of any lotions or oils. This will ensure that the sensor can detect the electrical signal generated by your retina.
• One sensor will be placed on your forehead, second sensor will be placed on the back of your head and a clip will be attached to your earlobe.
• The technician may ask you to cover the non- tested eye and will place the RETeval® device in front of your eye.
• You will see a red fixation light and a series of flashes of light. Continue to look at the red light for the duration of the test. Make sure to follow the technician’s instructions.