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Objective Electroretinography Testing to aid in the Diagnosis and Tracking of Glaucoma

Enhance the Glaucoma picture Measure ganglion cell function

The RETeval® PhNR testing is a vital tool in the management of patients with Glaucoma and other optic nerve diseases with objective ERG assessment of ganglion health.

Why conduct a PhNR ERG Glaucoma test?

Early diagnosis is essential to preserve vision loss from further degeneration of ganglion cells.

However, Glaucoma is often challenging to diagnose and manage. Testing such as perimetry and OCT imaging are standard of care, but are all too often hampered by media opacities (imaging for cup-to-disc-ratio), unspecific testing methods (IOP), or subjective and bothersome to complete (Visual field test).

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Did you know?
0 %
of true Glaucoma patients remain undiagnosed[41].
0 %
of Glaucoma patients are over-treated[41].

What is a PhNR Test?

PhNR stands for Photopic Negative Response and is an electroretinographic test for analyzing how the ganglion cells function.

During the Photopic Negative Response test with full-field flash ERG, the retina is illuminated with a red flash on blue background under light-adapted conditions. This last negative peak is derived from the ganglion cells and their axons and is generally used to evaluate subjects for Glaucoma.

The PhNR response from ERG is described by a time (implicit time) and amplitude. For Glaucoma diagnosis and management, several parameters are given as the disease itself is complex [37].

How does the RETeval make PhNR testing easier?

The RETeval PhNR test objectively measures the ganglion cells function by evaluating the electrical activity of the cells to a light stimulus. Knowing about the function of the ganglion cells assist in the detection and monitoring of glaucomateous changes in any patient.

The test provides high objectivity and repeatability, is independent from media opacities and is suitable also for patients with reduced motor and cognitive skills [31][32][34].

Dilation not required

Real time pupillography adjusts for pupil size in real time - can be used in patients who are not dilated or in any stage of dilation

No corneal contact

Our non-invasive LKC patented Sensor Strip skin electrodes mean no corneal electrode required

Simple to use & to interpret

Handheld, light and portable.
Train technicians in minutes.
Mac and Windows compatible

Diagnose Optic Nerve Dysfunction

The RETeval Device is expected to detect changes with a high degree of accuracy

Kita et al. have compared seven parameters of the RETeval PhNR test for their ability to differentiate between early or moderate Glaucoma from a healthy control group. In this study, high accuracy of the PhNR test was found [38].
accuracy
0 %

(Early Glaucoma)

Analyze the PhNR Amplitude at minimum

accuracy
0 %

(Moderate Glaucoma)

Analyze the PhNR W-ratio

Monitor Disease Changes

PhNR testing with the RETeval Device provides sensitive, objective monitoring of retinal changes for more informed follow-up, even where no changes in visual field or RNFL could be detected

Hui et al. detected improvements in the inner retinal function after treatment with nicotinamide, where no improvements in visual field or RNFL had been seen [39].

Glaukoma-treatment-graph2

Unleash the Power of ERG Glaucoma Testing with the RETeval

optimal test-retest capabilities

Our new algorithm provides a significant improvement in test/retest variability, leading to improved ability to track patient progress longitudinally. Additionally, the reference range is narrower, leading to an enhanced ability to aid in the detection of abnormal ganglion cell function.

Versatile, yet standardized

The protocol is ISCEV* compliant, uses the most effective stimuli settings, and is available in different configurations that allow physicians to adjust according to patient conditions (short and long test options, mydriatic and non-mydriatic).

*International Society for Clinical electrophysiology of Vision

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Sample Reports
The PhNR test report gives the amplitude and implicit time of the two first waves. The typical PhNR values such as amplitude and implicit time at the minimum are shown below the curves. For the support of a differential glaucoma diagnosis and management, other parameters have been analyzed by researchers, such as the W-ratio, which is calculated from the PhNR, a-, and b-wave amplitudes.

Sample Report

452DB777-D65E-4152-A88D-4833492FFE5B@2x PhNR – Glaucoma

Other clinical applications of the PhNR

Objective testing of ganglion cell function with the PhNR can be used to assess a range of optic nerve neuropathies [40]. This includes:
  • Ocular Hypertension
  • Leber Hereditary Optic Neuropathy
  • Optic Nerve Atrophy
  • Idiopathic Endocranial Hypertension
clinical applications
ERG test with the RETeval handheld device
Testimonials

Product Experience

We screen the patient as soon as they walk in the door, and then we test them every year to see what’s going on and see how the function of the retina is changing.
Pamela Weber, MD
Pamela Weber, MDRetina Specialist
Facing the pandemic of COVID 19 I appreciate the use of RETeval and other portable devices to minimize the patients move to too many rooms, thus hopefully limiting the spread of the diseases.
Dr. Igor Kozak
Dr. Igor KozakMoorfields Eye Hospital Abu Dhabi
There is a COVID19 positive little girl on the ward who needs an ERG to help with a possible NCL diagnosis, so that will be my first attempt of an ERG wearing full PPE!
RETeval user
RETeval userRETeval user
I am using RETeval since about 2 months and in this short time I was able to implement ERG with minimal disruption to clinic. The exams are done by our excellent nurse and she reports that patients are really cooperative.
Dr. Igor Kozak
Dr. Igor KozakMoorfields Eye Hospital Abu Dhabi
We have been very pleased with the RETeval. It has changed the way that we practice and has allowed us to significantly decrease the amount of EUAs with ERGs we perform. Furthermore, it has resulted in earlier diagnosis of patients with inherited retinal degenerations.
Melanie Schmitt, MD
Melanie Schmitt, MDUniversity of Wisconsin School of Medicine and Public Health
More Testimonials

Let’s Talk!

Request a demo or a quote for the RETeval

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© 2025 LKC Technologies, Inc.

California Proposition 65 information

Prop-65Warning: This product can expose you to chemicals including lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.

Substance Tables:

The table below lists substances which may be contained within LKC’s RETeval and RETevet products. Substances listed as Type 1 are within permissible levels in one or more of LKC’s products. Substances listed as Type 2 are used in the production of some components used in LKC products and may be present at trace levels, but are typically destroyed during processing. 

RETeval and RETevet Devices

Substance CAS # Type Listed as causing:
Nickel 7440-02-0 1 Cancer
Acrylonitrile 107-13-1 2
Ethylbenzine 100-41-4 2
Crystaline Silica 14808-60-7 1
Lead 7439-92-1 1 Cancer Developmental Toxicity Male Reproductive Toxicity Female Reproductive Toxicity
Methylene Chloride 75-09-2 2 Cancer Female Reproductive Toxicity
Bisphenol A 80-05-7 2
N-Hexane  110-54-3 2 Male Reproductive Toxicity