Diagnostic Monitoring Techniques for Light Sensitivity
Recruiting in Palo Alto (17 mi)
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: Randy Kardon
Must not be taking: Topical autonomics, sedatives, opioids
Disqualifiers: Glaucoma, diabetes, hypertension, others
No Placebo Group
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.12345
Is visual electrophysiological testing safe for humans?
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.24101112
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
Trial 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 (Procedure)
- Ocular Coherence Tomography (OCT) (Procedure)
- Pupillography (Procedure)
- Videography (Procedure)
- Wrist-watch sensor device (Device)
Trial OverviewThe 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
5Treatment groups
Active Control
Group I: TBI Patients without photosensitivityActive Control5 Interventions
Group II: Migraine patients without photosensitivityActive Control5 Interventions
Group III: Migraine patients with photosensitivityActive Control5 Interventions
Group IV: TBI patients with photosensitivityActive Control5 Interventions
Group V: Healthy Control subjectsActive Control5 Interventions
Find a Clinic Near You
Research Locations NearbySelect from list below to view details:
University of Iowa Health CareIowa City, IA
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Who Is Running the Clinical Trial?
Randy KardonLead Sponsor
References
Essentials of photometry for clinical electrophysiology of vision. [2021]Electrophysiological testing of the visual system requires familiarity with photometry. This technical note outlines the concepts of photometry with a focus on information relevant to clinical ERG and VEP testing. Topics include photometric quantities, consideration of pupil size, specification of brief extended flash stimuli, and the influence of the spectral composition of visual stimuli. Standard units and terms are explained in the context of the ISCEV standards and guidelines for clinical electrophysiology of vision.
ISCEV standard for clinical electro-oculography (2010 update). [2022]The clinical electro-oculogram (EOG) is an electrophysiological test of function of the outer retina and retinal pigment epithelium (RPE) in which changes in electrical potential across the RPE are recorded during successive periods of dark and light adaptation. This document presents the 2010 EOG Standard from the International Society for Clinical Electrophysiology of Vision (ISCEV: www.iscev.org ). This revision has been reorganized and updated, but without changes to the testing protocol from the previous version published in 2006. It describes methods for recording the EOG in clinical applications and gives detailed guidance on technical requirements, practical issues, and reporting of results. It is intended to promote consistent quality of testing and reporting within and between clinical centers.
Objective Pupillary Correlates of Photosensitivity in the Normal and Mild Traumatic Brain Injury Populations. [2017]No objective vision biomarker for photosensitivity currently exists. The present study sought to uncover potential biomarkers for photosensitivity within the pupillary light reflex.
[Electrophysiology in ophthalmology]. [2018]Electrophysiology is an objective functional test of the visual pathway and allows the location of visual dysfunctions to be detected. The flash electroretinogram (ERG) allows recognition of large area damage to the retina and can distinguish between rod and cone diseases by recording under both dark and light-adapted conditions. Specific stimulation techniques are used for the multifocal ERG (mfERG) which reveals localized retinal dysfunction, e. g. in maculopathies. The pattern ERG (PERG) is an indicator of ganglion cell function and can be used for early detection of glaucoma. The visual evoked potential (VEP) is a cortical response and serves as a functional test of the entire visual pathway from the eye to the visual system of the brain. After presenting each of these methods individually, the article gives assistance in situations where the appropriate electrophysiological method for a given clinical hypothesis is to be selected and explains how the methods can be combined in a reasonable way.
ISCEV Standard for clinical electro-oculography (2017 update). [2018]The clinical electro-oculogram (EOG) is an electrophysiological test of the outer retina and retinal pigment epithelium (RPE) in which changes in the electrical potential across the RPE are recorded during successive periods of dark and light adaptation. This document presents the 2017 EOG Standard from the International Society for Clinical Electrophysiology of Vision (ISCEV: www.iscev.org ). This standard has been reorganized and updated to include an explanation of the mechanism of the EOG, but without substantive changes to the testing protocol from the previous version published in 2011. It describes methods for recording the EOG in clinical applications and gives detailed guidance on technical requirements, practical issues and reporting of results with the main clinical measure (the Arden ratio) now termed the light peak:dark trough ratio. The standard is intended to promote consistent quality of testing and reporting within and between clinical centers.
An overview of drug development with special emphasis on the role of visual electrophysiological testing. [2018]Visual electrophysiological techniques, such as electroretinography (ERG) and visual evoked potentials (VEP) can provide useful information on the safety, efficacy, and proper dosing of chemical entities under development as new drug therapies. During post-marketing safety surveillance, a variety of visual electrophysiological measures can be used to objectively assess and document individual patient response to ophthalmic drugs and ocular or visual system side effects of non-ophthalmic drugs. In this paper, the discovery, exploratory development, full-development and post-marketing stages of drug development are briefly outlined. The potential role of visual electrophysiological techniques in each of these stages is described and discussed.
Steady-state electroretinograms and pattern electroretinograms in pigs. [2019]Electroretinograms (ERG) or pattern-electroretinograms (PERG) could be valuable for the quantification of potential damage to the pig retina by experimental erbium:YAG laser treatment. We therefore performed a normative study of ERGs and PERGs in pigs.
Retrospective evaluation of pre-surgical electroretinography results in a mixed-breed canine population presented for cataract removal surgery. [2023]Electroretinography (ERG) is used prior to cataract removal surgery to assess retinal function. We aimed to replicate and improve upon previous studies by performing a full ECVO protocol and by examining the retina post-surgery in all patients.
Retinal phototoxicity: a review of standard methodology for evaluating retinal optical radiation hazards. [2022]Optical radiation (light) safety standards can be difficult to use for the evaluation of light hazards to the retina, even for persons experienced in radiometry and photometry. This paper reviews terminology and methodology for evaluating optical radiation hazards to the retina in accordance with international standard ISO 15004-2 Ophthalmic instruments-Fundamental requirements and test methods, Part 2: Light hazard protection (2007). All optical radiation safety standards use similar methods. Specifically, this paper illustrates how to evaluate the retinal hazards from various ophthalmic instruments including the following: diffuse illumination of the cornea; incident light diverging at the cornea (direct ophthalmoscope, operation microscope, fixation lamp); and incident light converging at the cornea (indirect ophthalmoscope, fundus camera, slit lamp biomicroscope). A brief review of radiometry and the use of certified optical components by manufacturers as specified by the ISO standard is also provided. Finally, the authors provide examples of the use of photometric measurements in hazard evaluation.
[Information conveyed by electroretinography (author's transl)]. [2019]Clinical evaluation of the function of the human retina by subjective, psychophysical tests can be complemented by objective, electrophysiological methods such as electroretinography. The electroretinogram (ERG) is a transient action potential generated by the vertebrate retina in response to light. Using standardized stimulation, after assessing the normal range of the ERG the investigator can establish early diagnosis, improve prognostic statements and document the course of retinal diseases. A method to selectively stimulate the rod- and cone-system, developed by Gouras and co-workers, has proved to allow further differentiation of heredodegenerative diseases of the retina. The ERG monitors objectively the function of the retina in infants uncapable of cooperating in psychophysical tests and in patients suffering from opacities of the optic media. ERG results should be evaluated synoptically with psychophysical data, ophthalmoscopy, fluoresceinangiography and possibly with EOG and VER recordings. Under experimental conditions the ERG serves to monitor the sensitivity of the retina in vivo as well as in vitro in physiological, pharmacological and toxicological studies.
[Do We Still Need Electrophysiology in Ophthalmology?] [2017]Electrophysiological methods in clinical ophthalmology include the full-field electroretinogram (ERG) for assessment of outer and middle retinal layers, pattern ERG (PERG) for assessment of ganglion cell function, the electrooculogram (EOG) for assessment of retinal pigment epithelium function, as well as visual evoked potentials (VEP) for assessment of the visual pathway, including the optic nerve and visual cortex. Multifocal recording techniques for ERG and VEP are used for tests within selected areas of the visual field. Technical progress in ocular imaging, especially optical coherence tomography (OCT) and fundus autofluorescence (FAF), allows high-resolution imaging of subtle morphological changes of the retina and posterior fundus. Typical retinal diseases may then be diagnosed at an early stage, without conventional electrophysiological investigations (e.g. x-linked retinoschisis, Stargardt disease, vitelliform macular dystrophy). OCT outclasses electrophysiological methods in the quantification of optic atrophies. With newly developed optic techniques, peripheral retinal structures (wide angle optics) and subtle structures up to the photoreceptor level (adaptive optics) can be imaged with increasing quality. However, differentiation of central retinal disorders (e.g. macular dystrophy) from generalised retinal diseases requires electrophysiological diagnostic testing. The same applies to discrimination between different functional disorders in generalised retinal diseases (e.g. enhanced S-cone syndrome, congenital stationary night blindness, achromatopsia).
Electroretinography and visual evoked responses in paediatric practice. [2014]Electroretinography an the recording of visual evoked responses are of considerable value as ancillary investigations in clinical ophthalmology, paediatric neurology an developmental paediatrics. The techniques used are non-invasive and yield objective results without any need for patient co-operation. In this study 159 children were examined using a system constructed from apparatus available in South Africa. Indications for the investigations included developmental delay, acute intracranial disease, eye disease and cerebral degenerative disorders. Information obtained made possible distinctions between retinal dysfunction and lesions of optic pathways, the occipital cortex and higher cortical centres.