How Portable Electroretinography Can Support Optimal Care In Nursing Homes

How Portable Electroretinography Can Support Optimal Care In Nursing Homes

by Andrew Feltz, OD
REteval Diabetic Retinopathy Assessment

Managing Patients in Nursing Homes

Approximately 1.4 million people live in nursing homes across the US, with approximately 57% of these residents suffering from visual impairment 1,2. Approximately 40% of these visual impairments are classified as “avoidable blindness” when receiving appropriate care 3. However, gaining access to eye care is a challenge for residents and their families 4. 

This is why we developed a program with 360 Care that offers optometric services to nursing homes across 18 states. Providing optometric care directly within a nursing home can create several challenges for an Opto­metrist. One of these challenges is the availability of portable diagnostic instruments.  

Recently, a portable, hand-held device, with no direct contact required on the eye itself, has become available to measure the function of retinal cells objectively. I believe that this new device has a great deal of potential in a nursing home setting.

About Electroretinography

An electroretinogram (ERG) measures the electrical response of the photoreceptor cells, inner retinal cells, and ganglion cells after a light stimulus. Deviations in the time (implicit time) and strength (amplitude) of the response help to diagnose and monitor several diseases commonly present in nursing home populations. 

Although ERG has demonstrated usefulness in assisting in diagnosing and monitoring diseases such as diabetic retinopathy and glaucoma, previous device size and usability limitations have restricted the spread of ERG into the clinic. It is important to note that ERG is an objective measurement of retinal function. It is not dependent on the cognitive abilities of the patient and requires only minimal cooperation. As opposed to retinal imaging, ERG measurements are not sensitive to cataracts and allow us a comprehensive understanding of retinal function in the largest group of our patients 3. 

With the advent of a small, easy to use and truly portable device such as RETeval® device, ERG can become a valuable diagnostic tool for patients in nursing homes.

This is why we developed a program with 360 Care that offers optometric services to nursing homes across 18 states. Providing optometric care directly within a nursing home can create several challenges for an Opto­metrist. One of these challenges is the availability of portable diagnostic instruments.  

Recently, a portable, hand-held device, with no direct contact required on the eye itself, has become available to measure the function of retinal cells objectively. I believe that this new device has a great deal of potential in a nursing home setting.

Request a demo of the RETeval device

Clinical Evidence for ERG in Diabetic Retinopathy

The RETeval device comes with a test protocol called the DR Assessment. The DR Assessment test with the DR Score has been clinically validated in multiple cross-sectional and longitudinal studies to aid in the detection of Vision Threatening Diabetic Retinopathy (VTDR) and predict the risk of DR disease progression.  A recent study showed that patients having a DR score equal to or greater than 23.5 were 11 times more likely to have a future ocular intervention than patients having scores less than 23.5. 7 

Now, that I have a RETeval device with me during nursing home visits, I can quickly and comfortably monitor any resident with known or suspected diabetic retinopathy. I apply the skin electrodes, select the appropriate test from the device menu, follow the instructions on the device,  and get results immediately after the test. 

The easy-to-read report is color-coded, helping me quickly see abnormal values compared to the included reference data. In case of a high score, I can test further, see the patient more frequently, or refer them for treatment. 

This sample report of an 85-year-old patient with a DR score of 24.6 reveals that this patient is at a greater risk of developing VTDR.

Learn more about the RETeval device

Learn more about the RETeval device

A New Paradigm in Assessing Diabetic Retinopathy

Clinical Evidence for ERG in Glaucoma

As with diabetic retinopathy, the first measurement and analysis of glaucoma with ERG took place in the late 1940s 8. More recent evidence suggests that a specific component of the flash ffERG electrical response, the Photopic Negative Response (PhNR), is valid for assisting in assessing glaucomatous eyes 9,10. A recent study reported sensitivity as high as 85.4% and specificity as high as ≥ 95% 10. 

This high diagnostic accuracy gives me a higher confidence level when I cannot measure visual field defects but still need to screen for glaucoma.  The PhNR test is as easy to perform as the test for diabetic retinopathy.

The PhNR implicit times and amplitudes for both eyes are abnormal when compared against the age-adjusted reference data. These values are highlighted in red and indicate retinal ganglion cell stress, damage, and possible disease progression.

Learn more about the RETeval device

Learn more about the RETeval device

How RETeval Addresses My Needs

In my experience, the need for a quick and easy way to measure retinal function in nursing homes is critical, especially for patients with advanced cataracts or with patients who are uncooperative or cognitively impaired. 
  • The RETeval system is a truly portable, hand-held ERG device that allows the patient to remain in a comfortable position (lying or sitting in a wheelchair). Because the RETeval uses skin electrodes and does not require dilation 11, it is well tolerated by patients.
  • The RETeval system is easy to learn and has a very low screening failure rate reported as low as 1% 12. Most tests take less than 5 minutes, and results are available immediately both directly on the device, or as a PDF report when connected to any PC. These easy-to-read PDF reports include age-related reference data, highlighting results in green, yellow, or red.
  • Most Medicare jurisdictions also reimburse Full-field ERG under CPT code 92273.
  • Now, that I have a RETeval device with me during nursing home visits, I can quickly and comfortably monitor any resident with known or suspected diabetic retinopathy. I apply the skin electrodes, select the appropriate test from the device menu, follow the instructions on the device,  and get results immediately after the test.
  • The easy-to-read report is color-coded, helping me quickly see abnormal values compared to the included reference data. In case of a high score, I can test further, see the patient more frequently, or refer them for treatment.
  • A sample report of an 85-year-old patient with a DR score of 24.6 can be seen in Figure 2. This patient is at a greater risk of developing VTDR.

Overall...

"Having the RETeval system for my nursing home visits has been a great addition to my practice.  It has allowed me to easily assess the visual function of my patients where it would typically be difficult, if not impossible."

Dr. Andrew Feltz, OD
Dr. Andrew Feltz
About Dr. Andrew Feltz, OD​

References:

  1. https://www.nursinghomeabusecenter.org/informative/facts-statistics-nursing-homes/ accessed on May 6th 2020
  2. Owsley C, McGwin G, Scilley K, Meek GC, Dyer A, Seker D. The Visual Status of Older Persons Residing in Nursing Homes. Arch Ophthalmol. 2007;125(7):925–930. 
  3. Tielsch JM, Javitt JC, Coleman A, Katz J, Sommer A. The Prevalence of Blindness and Visual Impairment among Nursing Home Residents in Baltimore. New England Journal of Medicine. 1995;332(18):1205–1209. 
  4. Friedman DS, Muñoz B, Roche KB, Massof R, Broman A, West SK. Poor Uptake of Cataract Surgery in Nursing Home Residents: The Salisbury Eye Evaluation in Nursing Home Groups Study. Arch Ophthalmol. 2005;123(11):1581–1587. 
  5. Swanson MW, Achiron LR, Beebe KL, et al. OPTOMETRIC CARE OF NURSING HOME RESIDENTS. Published online 1998:81.
  6. Zeng, Yunkao, Dan Cao, Dawei Yang, Xuenan Zhuang, Honghua Yu, Yunyan Hu, Yan Zhang, Cheng Yang, Miao He, und Liang Zhang. „Screening for Diabetic Retinopathy in Diabetic Patients with a Mydriasis-Free, Full-Field Flicker Electroretinogram Recording Device“. Documenta Ophthalmologica, 2019.
  7. Brigell, Mitchell G., Bryce Chiang, April Yauguang Maa, und C. Quentin Davis. „Enhancing Risk Assessment in Patients with Diabetic Retinopathy by Combining Measures of Retinal Function and Structure“. Translational Vision Science & Technology 9, Nr. 9 (3. August 2020): 40–40.
  8. Leydhecker G. The Electroretinogram in Glaucomatous Eyes. Br J Ophthalmol. 1950;34(9):550–554.
  9. Kita, Yoshiyuki, Gábor Holló, Tsunehiro Saito, Yousuke Momota, Ritsuko Kita, Kazushige Tsunoda, und Akito Hirakata. „RETeval Portable Electroretinogram Parameters in Different Severity Stages of Glaucoma“. Journal of Glaucoma, April 2020.
  10. Kirkiewicz M, Lubiński W, Penkala K. Photopic negative response of full-field electroretinography in patients with different stages of glaucomatous optic neuropathy. Doc Ophthalmol. 2016;132(1):57–65. 
  11. Davis CQ, Kraszewska O, Manning C. Constant luminance (cd·s/m2) versus constant retinal illuminance (Td·s) stimulation in flicker ERGs. Doc Ophthalmol. 2017;134(2):75–87. 
  12. Maa AY, Feuer WJ, Davis CQ, et al. A novel device for accurate and efficient testing for vision-threatening diabetic retinopathy. J Diabetes Complicat. 2016;30(3):524–532