Diagnostic Monitoring Techniques for Light Sensitivity

Overseen By Julie Nellis, BSN

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Randy Kardon

Must not be taking: Topical autonomics, sedatives, opioids

Disqualifiers: Glaucoma, diabetes, hypertension, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 1

120 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial seeks new ways to diagnose and monitor light sensitivity and headaches by examining how eyes and nerves react to light. It employs various techniques, such as special eye scans and sensors, to measure these reactions. Methods include Electrophysiology (with tests like Electroretinography and Visual Evoked Potentials), Ocular Coherence Tomography (OCT), Pupillography, Videography, and a wrist-watch sensor device. The trial involves different groups: individuals with traumatic brain injuries (TBI) with and without light sensitivity, migraine sufferers with and without light sensitivity, and healthy individuals. Those with photosensitivity from other causes or a history of TBI may be suitable candidates. Participants should not have eye disorders or conditions that could affect eye or nerve responses. As an unphased trial, this study offers a unique opportunity to contribute to groundbreaking research that could improve diagnosis and monitoring methods for light sensitivity and headaches.

Will I have to stop taking my current medications?

You may need to stop taking certain medications, especially those that affect pupil size or are sedatives, like benzodiazepines or opioids, as they could interfere with the study measurements.

What prior data suggests that these diagnostic monitoring techniques are safe for light sensitivity?

Research shows that the diagnostic tools tested in this trial, including electrophysiology, OCT, pupillography, videography, and wrist-watch sensors, are generally safe for people.

Electrophysiology measures the eye's electrical activity. Studies have found it to be widely used and safe in both research and medical settings.

Ocular Coherence Tomography (OCT) scans the eye to take detailed pictures without invasive procedures. It is considered safe and is often used to diagnose eye conditions.

Pupillography measures the pupil's response to light. This well-known method requires little effort from the patient and is commonly used without reports of harm.

Videography and wrist-watch sensors are non-contact methods. Videography captures facial features, while wrist-watch sensors monitor light exposure and other data. Both are safe and do not involve risky procedures.

Overall, previous patients have well-tolerated these tools. They are non-invasive, meaning they do not involve surgery or entering the body, which generally means fewer risks. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about these diagnostic techniques for light sensitivity because they offer innovative ways to monitor and understand this condition. Unlike traditional methods that might only assess symptoms through patient self-reporting, these techniques use advanced tools like electrophysiology, which measures electrical activity in the eye, and Ocular Coherence Tomography (OCT), providing detailed images of the eye's internal structures. Pupillography and videography offer dynamic insights into how the pupils respond to light, while the wrist-watch sensor device allows for continuous, non-invasive monitoring of light exposure and sensitivity. Together, these methods could provide a more comprehensive understanding of light sensitivity, potentially leading to better-targeted treatments in the future.

What evidence suggests that these diagnostic monitoring techniques are effective for light sensitivity?

This trial will compare various diagnostic methods to understand light sensitivity and headaches across different participant groups. Research has shown that each method provides unique insights into these conditions. Electrophysiology, one method being tested, measures electrical signals in the eye and brain, with a 75% success rate in identifying visual problems and an 87.5% accuracy in ruling them out. OCT, another method in this trial, safely images eye health and accurately diagnoses eye conditions. Pupillography observes pupil responses to light, assessing deeper visual pathways in the brain. Videography studies how light affects headaches, with evidence suggesting that certain optical treatments can reduce light sensitivity. Wrist-watch sensors track light exposure in real-time, offering insights into how light influences mood and alertness. ^{5 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for healthy individuals aged 18-80 who have had a normal eye exam in the past year. It's designed to help those with traumatic brain injury and associated light sensitivity or migraines by objectively measuring their response to light.

Inclusion Criteria

Healthy individuals with normal eye exam in the previous year

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Assessment

Objective measurement of facial features, pupil responses, retinal electrical responses, and autonomic nerve responses to light

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after assessment

2-4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Electrophysiology
• Ocular Coherence Tomography (OCT)
• Pupillography
• Videography
• Wrist-watch sensor device

Trial Overview The study tests new methods like videography, ocular coherence tomography (OCT), wrist-watch sensor devices, pupillography, and electrophysiology to diagnose and monitor treatment of light sensitivity and headaches in patients.

How Is the Trial Designed?

Group I: TBI patients with photosensitivity Active Control 5 Interventions

Group II: TBI Patients without photosensitivity Active Control 5 Interventions

Group III: Migraine patients with photosensitivity Active Control 5 Interventions

Group IV: Migraine patients without photosensitivity Active Control 5 Interventions

Group V: Healthy Control subjects Active Control 5 Interventions

Who Is Running the Clinical Trial?

Randy Kardon

Lead Sponsor

Trials

4

Recruited

1,100+

Published Research Related to This Trial

The study identified specific pupillary light reflex parameters that differ significantly between individuals with and without photosensitivity, suggesting these could serve as objective biomarkers for photosensitivity.

In individuals with mild traumatic brain injury (mTBI), distinct differences in pupil response were observed, including larger baseline diameter and faster recovery times, indicating that pupillometry could help assess photosensitivity in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Objective Pupillary Correlates of Photosensitivity in the Normal and Mild Traumatic Brain Injury Populations. Truong, JQ., Ciuffreda, KJ.[2017]

The 2017 EOG Standard from ISCEV updates the guidelines for the clinical electro-oculogram test, which measures the electrical potential changes in the outer retina and retinal pigment epithelium during light and dark adaptation.

The standard emphasizes the importance of the light peak:dark trough ratio (previously known as the Arden ratio) as the main clinical measure, aiming to enhance consistency and quality in EOG testing across different clinical centers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

ISCEV Standard for clinical electro-oculography (2017 update). Constable, PA., Bach, M., Frishman, LJ., et al.[2018]

Electroretinograms (ERG) and pattern-electroretinograms (PERG) can be recorded in pigs, but the amplitudes are generally small, indicating that these methods may not be sensitive enough to detect minor retinal damage.

High variability in ERG and PERG measurements suggests that only significant retinal damage, such as that caused by vitrectomy or erbium:YAG laser treatment, would likely result in noticeable changes in these readings.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Steady-state electroretinograms and pattern electroretinograms in pigs. Janknecht, P., Wesendahl, T., Feltgen, N., et al.[2019]

Electrophysiological tests, like the flash electroretinogram (ERG) and multifocal ERG (mfERG), are effective in identifying and localizing visual dysfunctions, helping to distinguish between different types of retinal diseases.

The pattern ERG (PERG) can detect early signs of glaucoma by assessing ganglion cell function, while the visual evoked potential (VEP) evaluates the entire visual pathway, providing a comprehensive understanding of visual system health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Electrophysiology in ophthalmology]. Meigen, T.[2018]

Electroretinography and visual evoked responses are effective non-invasive techniques for assessing visual function in children, providing objective results without requiring patient cooperation.

In a study of 159 children, these techniques helped differentiate between retinal dysfunction and issues in the optic pathways or higher brain centers, aiding in the diagnosis of various neurological and eye conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electroretinography and visual evoked responses in paediatric practice. Leary, PM., Pietersen, M.[2014]

In a study involving 127 eyes from 67 dogs undergoing cataract surgery, it was found that the amplitudes of rod and cone responses decreased significantly with the advancement of cataracts, indicating a potential impact on retinal function.

The study suggests that lower electroretinography (ERG) amplitudes in dogs with cataracts may be attributed to aging or cataract severity rather than underlying retinal disease, which is important for interpreting ERG results before surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retrospective evaluation of pre-surgical electroretinography results in a mixed-breed canine population presented for cataract removal surgery. Wegg, ML., Pollard, D., Ofri, R.[2023]

Understanding photometry is crucial for accurate electrophysiological testing of the visual system, particularly in clinical settings like ERG (electroretinography) and VEP (visual evoked potential) testing.

The technical note emphasizes the importance of factors such as pupil size, flash stimulus specifications, and the spectral composition of visual stimuli, all of which are essential for adhering to ISCEV standards in clinical electrophysiology.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Essentials of photometry for clinical electrophysiology of vision. McCulloch, DL., Hamilton, R.[2021]

The paper reviews the challenges in applying optical radiation safety standards for assessing retinal hazards, emphasizing the need for clear terminology and methodology as outlined in the ISO 15004-2 standard.

It provides guidance on evaluating retinal hazards from various ophthalmic instruments, highlighting the importance of using certified optical components and photometric measurements for accurate hazard assessment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Retinal phototoxicity: a review of standard methodology for evaluating retinal optical radiation hazards. Landry, RJ., Bostrom, RG., Miller, SA., et al.[2022]

Electroretinography (ERG) is an objective method that measures the electrical response of the retina to light, allowing for early diagnosis and monitoring of retinal diseases, especially in patients who cannot participate in subjective tests.

The ERG can differentiate between rod and cone function, which is particularly useful for diagnosing hereditary retinal diseases and can be used alongside other methods like psychophysical tests and imaging techniques for comprehensive evaluation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Information conveyed by electroretinography (author's transl)]. Niemeyer, G.[2019]

Visual electrophysiological techniques like electroretinography (ERG) and visual evoked potentials (VEP) are valuable tools for assessing the safety and efficacy of new ophthalmic drug therapies during their development and post-marketing phases.

These techniques can objectively measure patient responses to eye medications and detect side effects from non-eye-related drugs, highlighting their importance in monitoring ocular health throughout the drug lifecycle.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An overview of drug development with special emphasis on the role of visual electrophysiological testing. Brigell, M., Dong, CJ., Rosolen, S., et al.[2018]

Electrophysiological methods, such as electroretinograms (ERG) and visual evoked potentials (VEP), are essential for assessing specific retinal functions and diagnosing various retinal diseases, especially when differentiating between central and generalized retinal disorders.

Recent advancements in imaging techniques like optical coherence tomography (OCT) provide high-resolution images of the retina, allowing for early diagnosis of diseases without the need for traditional electrophysiological tests, although these tests remain crucial for certain conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Do We Still Need Electrophysiology in Ophthalmology?] Tegetmeyer, H.[2017]

The 2010 EOG Standard from ISCEV provides updated guidelines for conducting electro-oculogram tests, which assess the function of the outer retina and retinal pigment epithelium, ensuring consistency in testing across clinical centers.

While the testing protocol remains unchanged from the 2006 version, the updated document emphasizes technical requirements and practical issues to enhance the quality of EOG testing and result reporting.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

ISCEV standard for clinical electro-oculography (2010 update). Marmor, MF., Brigell, MG., McCulloch, DL., et al.[2022]

Citations

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What can visual electrophysiology tell about possible visual ... The field-specific VEP had a sensitivity of 75% and a specificity of 87.5% [55]. This technique was further developed by Hébert-Lalonde et al. [56, 57] that ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S0042698920300857

Developments in non-invasive visual electrophysiology Two main techniques are available: the electroretinogram (ERG), a mass potential originating in the retina, and the visual evoked potential (VEP).

3. nature.com nature.com/articles/s41433-024-03154-6

Electrodiagnostic tests of the visual pathway and ... This article describes the main visual electrodiagnostic tests relevant to neuro-ophthalmology practice, including the visual evoked potential (VEP),

4. mdpi.com mdpi.com/2218-273X/12/10/1390

Use of Visual Electrophysiology to Monitor Retinal and ... Electrophysiologic changes reported with EON include a reduction in the difference of the maximum b-wave amplitude relative to the maximum a- ...

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC10397240/

Visual electrophysiology and “the potential of the potentials” Electrophysiology permits direct, objective and quantitative assessment of function, both at the level of the visual cortex (visual evoked potentials, VEPs) and ...

6. ncbi.nlm.nih.gov ncbi.nlm.nih.gov/books/NBK11553/

The Electroretinogram and Electro-oculogram: Clinical ... - NCBI The ERG is a test used worldwide to assess the status of the retina in eye diseases in human patients and in laboratory animals used as models of retinal ...

7. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0920121120300449

Characteristics of visual evoked potentials related to the ... In this study, we analysed visual evoked potentials (VEPs) in three different samples: i) 38 photosensitive patients (21 males, 17 females; mean age 10.0 ± 2.9 ...

8. nature.com nature.com/articles/s41433-021-01614-x

Clinical electrophysiology of the optic nerve and retinal ... The electrophysiology of the optic nerve and RGCs has been well established through the Visual Evoked Potential (VEP) and Pattern ...

9. nationwidechildrens.org nationwidechildrens.org/specialties/eye-care-ophthalmology/visual-electrophysiology

Visual Electrophysiology The visual evoked potential (VEP) provides important diagnostic information regarding the functional integrity of the visual system. It measures the electrical ...