Electroretinography (ERG) has emerged as a transformative tool in optometric practice, enabling eye care professionals to assess retinal function with unprecedented accuracy. In a recent podcast episode, Dr. Chris Lievens and Dr. Timothy Earley delved into the evolving role of ERG in managing chronic eye diseases, particularly diabetic retinopathy. This article explores the insights shared during their conversation, focusing on the practical applications of ERG, its impact on patient care, and its future potential in optometry.

Electroretinography (ERG) is a diagnostic test that measures the electrical responses of various cell types in the retina, including photoreceptors, inner retinal cells, and ganglion cells. ERG serves as a functional assessment, akin to an EKG for the eyes, providing critical information about retinal health that structural imaging alone cannot reveal.

This ability to assess retinal function makes ERG particularly valuable in monitoring diseases like diabetic retinopathy, macular degeneration, and other chronic conditions that can impact vision.

Traditionally, ERG was confined to research settings due to the complexity of the equipment and testing protocols. However, advancements have led to the development of more practical, handheld ERG devices that integrate seamlessly into everyday optometric practice.

Dr. Earley highlighted how these newer devices simplify the testing process:

• 
  
• Handheld Convenience: Portable ERG devices can be used directly in the exam room, reducing the need for specialized facilities.
  
  
• Non-Invasive Testing: The test is quick, taking only 15 to 30 seconds per eye, and does not require pupil dilation or dark adaptation for diabetic protocols.
  
  
• Actionable Results: ERG provides a DR score that helps predict the need for interventions like anti-VEGF injections.
  

1. Monitoring Diabetic Retinopathy
ERG’s ability to generate a Diabetic Retinopathy (DR) score allows optometrists to track disease progression objectively. A DR score combines data from signal strength, speed, and pupil response, offering a quantifiable metric to assess the likelihood of needing retinal interventions.

• 
  
• Real-Time Insights: ERG testing can be conducted during a routine exam if diabetic retinopathy is detected, eliminating the need for follow-up appointments.
  
  
• Patient Education: Showing patients their DR scores and waveforms can enhance compliance with treatment plans.
  

2. Detecting Functional Deficits in AMD (Age-Related Macular Degeneration)
While structural imaging focuses on visible changes, ERG can detect functional deficits in the retina that precede visible damage. This makes it an invaluable tool for early intervention in conditions like AMD.

3. Beyond Diabetes and AMD: Emerging Uses

• 
  
• Glaucoma Monitoring: Ongoing studies are investigating ERG’s potential for creating a risk score similar to the DR score for glaucoma patients.
  
  
• Pediatric Applications: ERG protocols are being adapted for visual evoked potentials (VEP) to assess pediatric patients.
  

A common misconception is that ERG and Optical Coherence Tomography (OCT) are redundant. While OCT excels in assessing structural changes, ERG provides a functional assessment, allowing optometrists to correlate structure with function.

The combination of OCT and ERG enables a comprehensive evaluation, particularly in chronic diseases like diabetic retinopathy and AMD, where structure-function disparity is common.

1. Expanding Protocols:
Current research is exploring the adaptation of ERG protocols for other retinal diseases and systemic conditions impacting ocular health.

2. Enhancing Accessibility:
The development of user-friendly, handheld ERG devices is democratizing access to advanced retinal diagnostics for smaller practices.

3. Standardization and Training:
As ERG becomes more integrated into routine care, standardizing protocols and ensuring adequate training for optometric technicians will be crucial.

4. Insurance and Reimbursement:
ERG testing is reimbursable under multiple CPT codes, making it a financially viable addition to practice. However, ongoing advocacy is needed to expand insurance coverage for newer protocols.

• 
  
• Start with Diabetic Protocols: Begin by integrating ERG testing for patients with diabetic retinopathy, where it offers immediate diagnostic value.
  
  
• Invest in Training: Ensure technicians are trained in electrode placement and test administration for consistent results.
  
  
• Educate Patients: Use visual aids to explain test results, reinforcing the importance of ongoing monitoring.