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

Trial Summary

What is the purpose of this trial?

This trial uses tools to measure how a person's face, eyes, and nerves react to light. It targets people with light sensitivity and headaches, including those with traumatic brain injuries and migraines. By understanding these reactions, doctors aim to develop better treatments for these conditions.

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 data supports the effectiveness of this treatment for light sensitivity?

Electrophysiology tests like ERG and VEP are used to detect visual dysfunctions and can help identify issues in the visual pathway, which may be related to light sensitivity. These tests are standardized to ensure consistent quality, which supports their reliability in diagnosing and monitoring conditions related to light sensitivity. ^{1 2 3 4 5}

Is visual electrophysiological testing safe for humans?

Visual electrophysiological techniques like electroretinography (ERG) and visual evoked potentials (VEP) are used to assess the safety of drugs and their effects on the eyes, indicating they are generally considered safe for evaluating visual system side effects. ^{1 6 7 8 9}

How does this treatment for light sensitivity differ from other treatments?

This treatment uses electrophysiological techniques like electroretinography (ERG) and visual evoked potentials (VEP) to objectively assess and monitor retinal and visual pathway function, which is unique compared to other treatments that may rely on subjective assessments or imaging alone. These methods can detect specific dysfunctions in the retina and visual system, providing a detailed understanding of light sensitivity issues. ^{2 4 10 11 12}

Eligibility Criteria

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

I am between 18 and 80 years old.

Healthy individuals with normal eye exam in the previous year

Timeline

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

Treatment Details

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.

Participant Groups

Group I: Migraine patients with photosensitivity Active Control 5 Interventions

Group II: TBI patients with photosensitivity Active Control 5 Interventions

Group III: TBI Patients without 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+

Findings from Research

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 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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

References

1. Netherlands pubmed.ncbi.nlm.nih.gov

Essentials of photometry for clinical electrophysiology of vision. [2021]

2. Netherlands pubmed.ncbi.nlm.nih.gov

ISCEV standard for clinical electro-oculography (2010 update). [2022]

3. England pubmed.ncbi.nlm.nih.gov

Objective Pupillary Correlates of Photosensitivity in the Normal and Mild Traumatic Brain Injury Populations. [2017]

4. Germany pubmed.ncbi.nlm.nih.gov

[Electrophysiology in ophthalmology]. [2018]

5. Netherlands pubmed.ncbi.nlm.nih.gov

ISCEV Standard for clinical electro-oculography (2017 update). [2018]

6. Netherlands pubmed.ncbi.nlm.nih.gov

An overview of drug development with special emphasis on the role of visual electrophysiological testing. [2018]

7. Germany pubmed.ncbi.nlm.nih.gov

Steady-state electroretinograms and pattern electroretinograms in pigs. [2019]

8. England pubmed.ncbi.nlm.nih.gov

Retrospective evaluation of pre-surgical electroretinography results in a mixed-breed canine population presented for cataract removal surgery. [2023]

9. United States pubmed.ncbi.nlm.nih.gov

Retinal phototoxicity: a review of standard methodology for evaluating retinal optical radiation hazards. [2022]

10. Germany pubmed.ncbi.nlm.nih.gov

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

11. Germany pubmed.ncbi.nlm.nih.gov

[Do We Still Need Electrophysiology in Ophthalmology?] [2017]

12. South Africa pubmed.ncbi.nlm.nih.gov

Electroretinography and visual evoked responses in paediatric practice. [2014]