Clinical trial NCT01942564: The Head Injury-associated Photosensitivity and Pupillary Function (HIPP) Study
Official title: The Head Injury-associated Photosensitivity and Pupillary Function (HIPP) Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Head Injury
Traumatic Brain Injury (TBI)
Photosensitivity
Photophobia
Keywords: traumatic brain injury
photophobia
photosensitivity
pupil
Lead sponsor: Ohio State University
Sponsor class: OTHER
Collaborators: name: U.S. Army Medical Research and Development Command
First posted: 2013-09-16
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Cases: Age 18 or older with symptoms of increased photosensitivity since experiencing a head injury.

Controls: Matched to cases in age, sex and race.

Brief summary: After a head injury, many people find that exposure to light causes them increased discomfort. By measuring how the pupil in the eye constricts to flashes of red and blue light, this study will investigate whether this phenomenon is due to a change in the eye's sensitivity to light.

Detailed description: The pupils inside the eyes constrict in response to light stimulation. Different classes of cells within the human retina initiate this response. Recent research suggests that one of the ganglion cell types involved in this pupil response also plays a role in the photophobia experienced by migraine sufferers. The main aim of this study is to determine whether this type of ganglion cell becomes 'hypersensitive' after traumatic brain injury, thereby contributing to symptoms of increased photosensitivity experienced by many of these individuals.

In the first session of this study, subjects will be asked questions about their sensitivity to light and the reaction of their eyes' pupils to flashing red and blue lights will be measured. The subjects will be given a full eye examination to rule out other causes of increased photosensitivity.

In some cases, subjects will be asked to attend a second session roughly two weeks later. They will be asked to wear a watch that measures their daily activity/sleep rhythms and light exposure during this inter-session period. During the second session, further testing of the pupil responses to blue and red flickering light will be performed.

Eligibility criteria: Inclusion Criteria:

* 18+ years old
* reports a previous head injury that occurred at least 6 months ago
* score of 2 or 3 (mild TBI) on OSU-TBI ID Survey
* best-corrected visual acuity of at least 20/30 in both eyes
* reliable visual field

Exclusion Criteria:

* pregnancy
* significant afferent pupillary defect
* previous history of neurodegenerative disease
* intraocular pressure more than 21 mm Hg
* significant visual field defect
* active corneal pathology
* history of retinal or optic nerve disease
* strabismus (eye turn)

Primary outcomes:
measure: Pupil Responses
timeFrame: 2 weeks
Secondary outcomes:
measure: Sleep Rhythms
timeFrame: 2 weeks
measure: Light Exposure
timeFrame: 2 weeks
measure: Photosensitivity Symptoms
timeFrame: Single visit - one day
Other outcomes:
Locations:
city: Columbus
country: United States
facility: College of Optometry
state: Ohio
Study officials:
affiliation: Ohio State University
name: Andrew Hartwick, OD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Barker F, Cockerham G, Goodrich G, Hartwick A, Kardon R, Mick AB, Swanson M. Brain Injury Impact on the Eye and Vision. Optom Vis Sci. 2017 Jan;94(1):4-6. doi: 10.1097/OPX.0000000000001001. No abstract available.
citation: Yuhas PT, Shorter PD, McDaniel CE, Earley MJ, Hartwick AT. Blue and Red Light-Evoked Pupil Responses in Photophobic Subjects with TBI. Optom Vis Sci. 2017 Jan;94(1):108-117. doi: 10.1097/OPX.0000000000000934.