Photophobia, Traumatic Brain Injury, Migraine
Conditions
Brief summary
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.
Detailed description
Using objecting measurement of facial features, pupil responses, retinal electrical responses and autonomic nerve responses to light this project aims to provide a new framework for diagnosing and monitoring treatment of light sensitivity. The patient's responses will be measured with videography facial muscle electrical responses Electromyogram (EMG) measured from surface skin electrodes and retinal electrical responses (EMG) or electroretinogram (ERG) recorded from a portable hand-held device). Simultaneously, patient's will have their heart rate and skin conductance objectively monitored using wristwatch devices (E4, Empatica). If successful, this will open an immediate new way to objectively assess the mechanisms that lead to light sensitivity, and provide an approach to effectively treat, and manage the symptoms of light sensitivity and headache from different causes, including traumatic brain injury (TBI) and migraine.
Interventions
DEVICEPupillography
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.
DEVICEOcular Coherence Tomography (OCT)
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.
DEVICEWrist-watch sensor 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).
DEVICEVideography
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.
DEVICEElectrophysiology
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.
Sponsors
Randy Kardon
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SCREENING
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy Control subjects: Inclusion Criteria * Healthy individuals with normal eye exam in the previous year * Age 18-80
Exclusion criteria
* 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 TBI patients without photosensitivity or headache: Inclusion Criteria * Age 18-80 * Traumatic Brain Injury (TBI)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Correlation of facial responses to light sensitivity | 1 Day | Hand held pupillography/videography, electroretinogram, and electrophysiology measurements are correlated to develop of an objective biological marker of light sensitivity. |
| Difference in objective biological markers of light sensitivity between light sensitive and normal subjects | 1 Day | The correlation of facial responses to light sensitivity is compared between groups to test whether the measure can accurately distinguish light sensitivity. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Correlation of objective biological marker of light sensitivity to optic nerve structures | 1 Day | 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. |
| Correlation of objective biological marker of light sensitivity to macula (structure found in the back of the eye). | 1 Day | 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). |
Countries
United States
Contacts
Primary ContactJulie Nellis, BSN
Backup ContactJan Full, BSN
Outcome results
None listed