Name of the Procedure:

Electroretinography (ERG)

Summary

Electroretinography (ERG) is a diagnostic test that measures the electrical activity of the retina, the light-sensitive layer at the back of the eye. This helps doctors evaluate how the retina is functioning.

Purpose

ERG is used to diagnose and monitor various eye conditions, such as retinal dystrophies, diabetic retinopathy, and other disorders affecting the retina. The goal is to detect abnormalities in retinal function to guide treatment decisions.

Indications

Specific symptoms or conditions that may warrant an ERG include:

• Unexplained vision loss
• Night blindness
• Retinal degeneration
• Family history of inherited retinal diseases

Patient criteria:

• Presence of symptoms suggesting retinal dysfunction
• Routine monitoring for those diagnosed with retinal conditions

Preparation

• Patients may be instructed to avoid caffeine and certain medications before the test.
• Contact lenses should be removed.
• Pupils may be dilated using special eye drops for better results.
• No fasting is required.

Procedure Description

1. The patient is seated comfortably in a darkened room.
2. Special eye drops are applied to numb and dilate the eyes.
3. A small electrode is placed on the surface of the eye or on the skin near the eye.
4. The patient is then asked to look at flashing lights or patterns while the electrical responses of the retina are recorded through the electrode.
5. Multiple tests may be conducted to measure responses under different lighting conditions.

Tools and equipment:

• ERG machine
• Electrodes
• Eye drops for numbing and dilation

Anesthesia:

• Local anesthetic eye drops to numb the eye

Duration

The procedure typically takes about 30 to 60 minutes.

Setting

ERG is usually performed in an ophthalmologist's office or a specialized outpatient clinic.

Personnel

• Ophthalmologist or a trained technician

Risks and Complications

• Mild discomfort or irritation due to the electrode or eye drops
• Rarely, a temporary increase in eye pressure

Benefits

• Provides crucial information about retinal function
• Helps in early diagnosis of retinal disorders
• Guides treatment plans and monitoring of retinal diseases Expected benefits are usually realized immediately upon interpretation of the results.

Recovery

• Most patients can resume normal activities immediately.
• Temporary blurred vision from dilating drops usually resolves within a few hours.
• Follow-up appointments may be scheduled based on the results.

Alternatives

Other diagnostic options may include:

• Visual field tests
• Optical coherence tomography (OCT)
• Fundus photography Pros and cons:
• ERG provides direct measurement of retinal function, which other tests may not offer.
• Other imaging tests may be non-invasive and quicker but may not give as detailed a functional analysis.

Patient Experience

During the procedure, patients might experience:

• Mild discomfort from the electrode and eye drops
• Sensitivity to light due to pupil dilation After the procedure:
• Temporary blurred vision
• Mild eye irritation, which usually resolves quickly Pain management:
• The procedure is generally painless due to the numbing effect of the eye drops.