Health TrialsbyHealthPanel

Objectively Diagnose and Monitor Treatment of Light Sensitivity

ConditionsPhotophobiaTraumatic Brain InjuryMigraine
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-80
SponsorRandy Kardon

About this trial

The purpose of this project is to provide a new framework for diagnosing and monitoring treatment of light sensitivity and headache by objective measurement of facial features, pupil responses, retinal electrical responses and autonomic nerve responses to light.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Healthy individuals with normal eye exam in the previous year

Age 18-80

Disqualifiers

History of eye or systemic disorder that affect the retina, optic nerve, visual pathway, or pupil defect: including glaucoma, optic neuropathy, or retinal disease, diabetes and/or hypertension that are not well controlled, history of head trauma, concussion, or TBI, history of cervical or spinal injury/surgery

Medications or eyedrops that would confound measuring the pupil light reflex and EMG: including topical autonomic drugs that could influence pupil size, ocular pharmacologic agents, sedative agents (e.g. benzodiazepines or barbiturates), opioid narcotics

Must not be light sensitive or get migraine headaches

Age 18-80

Trial design

Design model

Parallel

Treatments tested in this trial

  • Pupillography

    Device

    A hand-held pupillometer/electroretinogram device (RETeval, LKC) will be held in front of the subject's eye, but will not touch the eye. The device will provide a brief, a series of brief light stimuli and then record the pupil response and the elicited electrical response from the retina from a surface skin patch (electrode) placed below each eye, from the light as a measure of whether the inherent sensitivity of the eye in the retina is normal. The investigators will repeat this in the left eye. The visible light stimulus is safe and is given at an intensity experienced in normal daily light exposures. The test takes about 2 minutes per eye.

  • Ocular Coherence Tomography (OCT)

    Device

    The thickness of the optic nerve and macula will also be measured inside of the eye using a special camera that forms an image of the layers of the retina without pupil dilation. The imaging is harmless and measures the structural health of the optic nerve and retinal layers. This test takes 5-10 minutes per eye.

  • Wrist-watch sensor device

    Device

    A wrist-watch sensor device (E4, Empatica) will be place on each wrist to measure skin conductance, heart rate, skin temperature and arm movement during testing. These wrist-watch devices are being used to monitor changes in sympathetic nerve activity to light intensity, (the sympathetic nerves supply the blood vessels to the skin and heart).

  • Videography

    Device

    The subject will sit comfortably in front of miniature combination infrared/visible light video cameras and infrared diode light source located within 1 meter to provide video recording of the face during testing with light and during darkness, described next. After the 10 minutes of dark-adapting, the subject will put his/her chin on a chin rest in front of the video cameras and a light emitting diode (LED) array give diffuse red, blue, and white stimuli over a range of intensities. None of the stimuli are as bright as a flash from a camera and are in the range of intensities normally experienced during daily activities. At the end of the test the investigators will add filters over the glasses: orange (blue-blocking) filters and neutral density filters. Subjects will grade independently, both the brightness and discomfort they feel from each light stimulus intensity.

  • Electrophysiology

    Device

    Next, electrodes will be placed above, below and to the side of the test eye to record the electromyogram (EMG) for measuring eyelid opening and blink rate.

Treatment groups

120 Participants
are divided into 5 treatment groups
Group A: Healthy Control subjectsActive comparator 5 interventions
Group B: TBI Patients without photosensitivityActive comparator 5 interventions
Group C: Migraine patients without photosensitivityActive comparator 5 interventions
Group D: Migraine patients with photosensitivityActive comparator 5 interventions
Group E: TBI patients with photosensitivityActive comparator 5 interventions

Trial outcomes

Primary outcomes

1

Correlation of facial responses to light sensitivity

Hand held pupillography/videography, electroretinogram, and electrophysiology measurements are correlated to develop of an objective biological marker of light sensitivity.

Time frame
1 Day
2

Difference in objective biological markers of light sensitivity between light sensitive and normal subjects

The correlation of facial responses to light sensitivity is compared between groups to test whether the measure can accurately distinguish light sensitivity.

Time frame
1 Day

Secondary outcomes

1

Correlation of objective biological marker of light sensitivity to optic nerve structures

Bio marker score will be correlated to optic nerve structure measurements made using Optical Coherence Tomography (OCT) to evaluate structural loss of the optic nerve.

Time frame
1 Day
2

Correlation of objective biological marker of light sensitivity to macula (structure found in the back of the eye).

Bio marker score will be correlated to macula structure measurements made using Optical Coherence Tomography (OCT) to examine to evaluate structural loss of the macula (structure found in the back of the eye).

Time frame
1 Day

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Randy Kardon

Lead sponsor

University of Iowa

Sponsor institution

Source ClinicalTrials.gov
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