Handheld ERG has been a game-changer in my practice. It has helped me better manage my patients with diabetes while boosting my bottom line. The RETeval ERG from LKC Technologies is a full-field ERG device that gathers functional data at an affordable price point while providing a fair reimbursement. Initially, I thought this sounded too good to be true, but after seamlessly integrating this technology into my practice, I now believe that the RETeval full-field ERG test has the potential to change the way we perform functional testing in 2024 in much the same way that OCT testing changed the way we perform structural testing in years past.

ERG 101

Electroretinography (ERG) measures the electrical responses of various cell types in the retina, including the photoreceptors (rods and cones), inner retinal cells (bipolar and amacrine cells), and the ganglion cells in response to a stimulus. As light passes through the eye and onto the retina, responses to the stimulus are shown as a waveform. The retinal photoreceptors (rods and cones) absorb the light before converting the stimulus. This is known as the A-wave or implicit time. A delay in implicit time (abnormal A wave) indicates cellular stress. 

Next, the light gets converted into electrochemical impulses that get transmitted to the bipolar cells. This is known as the B-wave or amplitude. A reduced amplitude (abnormal B Wave) indicates cells are dying or the number of healthy cells is decreasing. The bipolar cells effectively transfer information from rods and cones to the retinal ganglion cells, which are responsible for carrying visual information from the eye to the brain, this is known as the photopic negative response (PhNR) wave. An abnormal PhNR is indicative of reduced function of the retinal ganglion cells and is most common in conditions that affect the optic nerve, including ischemic optic neuropathy and glaucoma.

ERG in Practice

ERG testing with the RETeval is simple and only takes a few minutes thanks to FDA-cleared adhesive Sensor Strip Electrodes that are placed under each eye providing improved patient comfort since no corneal contact is required. The Sensor Strips connect to the handheld device with a quick and easy wire clip attachment. Each sensor strip contains 3 electrodes to reduce placement variability.

Constant pupil tracking allows for reliable, repeatable results. The device dynamically changes the stimulus intensity according to the pupil size to deliver a constant retinal illuminance during testing, which reduces the variability of measurement results caused by pupil size.

DR Score

My favorite feature of the device is the DR Assessment protocol, which produces a DR Score (diabetic retinopathy score) that can help predict whether a patient may require treatment. This score is determined by four parameters: implicit time, amplitude, pupil response and patient age. We know that ischemic changes of the iris can cause reduced or sluggish pupil responses over time in patients with diabetes. By taking the best eye’s implicit time and amplitude and combining it with the worse eye’s pupil response and patient’s age, a DR Score is determined.

If a patient’s RETeval DR Score is less than 23.5, the risk of surgical intervention in the next three years varies from 6% to 18%, depending upon their level of non-proliferative diabetic retinopathy (NPDR). If the patient’s DR Score is greater than 23.5 and they have severe NPDR, the risk of surgical intervention in the next three years increases to 67%. With a DR Score over 26, surgical intervention may be needed within 1 year. 

The DR Score can worsen with inadequate diabetic control, but it can also improve with successful diabetic management. By educating the patient and their diabetic health care provider of their diabetic retinopathy status and RETeval DR Score, we can assist the diabetic health care provider in managing our patient’s diabetes and reduce the risk for referral to a retinal specialist for surgical intervention and potential vision loss.

Thanks to functional testing with the RETeval ERG, when combined with  structural testing with dilated retinal examination, UWF fundus photography and SD-OCT, I am now able to DETECT retinal disease earlier, PREDICT the progression of the disease, FOLLOW up on the course of the disease and MONITOR treatment success for my patients with diabetes in a way that was not possible in the past but now is thanks to the RETeval ERG with DR Score.

ERG Is Profitable

The RETeval helps me address the retinal health of my patients, but it also boosts the bottom line and financial health of our practices in the following ways: 

  1. Reimbursement: The local Medicare reimbursement in San Antonio where I practice for code 92273 (full field ERG) is $122.66 (the national average reimbursement of $126 as a bilateral test). Compare that to 92250 (fundus photography) at $36.39 and 92134 (OCT of the retina) at $39.77. Best of all, there are no competing codes, so fundus photography, OCT and/or visual fields can be performed and reimbursed on the same day as RETeval ERG with one of more than 560 approved ICD-10 codes.
  2. Equipment cost: The RETeval ERG is very cost effective compared to other equipment. The cost of a RETeval device is in the low to mid 20s. Compare that to the cost of a SD-OCT or UWF fundus camera. Lower entry costs help with cash flow.
  3. ROI: Thanks to the reimbursement rate and low relative equipment cost of the RETeval ERG, the return on investment (ROI) is extremely fast. If a practice performs two RETeval ERG tests per day, the practice will earn back their ROI in approximately six months. 

I have two practices with a RETeval ERG device at each location. We use them every day, primarily for our patients with diabetic retinopathy. With the small footprint of the device, the smooth integration of implementing this test into our daily clinic schedule, the ease of use by our technicians and the easy-to-read and interpret color-coded exam reports for our doctors, the RETeval ERG has most definitely been a fantastic addition for diabetes management in our clinic and is great for both patient care and for the practice bottom line.