Clinical Trial: The Head Injury-associated Photosensitivity and Pupillary Function (HIPP) Study

Study Status: Completed
Recruit Status: Unknown status
Study Type: Observational

Official Title: The Head Injury-associated Photosensitivity and Pupillary Function (HIPP) Study

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 Summary:

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.


Sponsor: Ohio State University

Current Primary Outcome: Pupil Responses [ Time Frame: 2 weeks ]

The pupil fluctuation evoked by blue and red flickering lights will be measured in patients with a prior brain injury and compared to matched controls.


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Sleep Rhythms [ Time Frame: 2 weeks ]
    Daily rhythms of sleep and activity will be assessed in subjects with prior brain injury and compared to matched controls.
  • Light Exposure [ Time Frame: 2 weeks ]
    The exposure to red, blue and green components of the light spectrum will be quantified in patients with a prior brain injury, and compared to matched controls.
  • Photosensitivity Symptoms [ Time Frame: Single visit - one day ]
    Subjects will complete survey indicating symptoms they have experienced related to light sensitivity and will grade their discomfort after exposed to brief flashes of light.


Original Secondary Outcome: Same as current

Information By: Ohio State University

Dates:
Date Received: September 6, 2013
Date Started: August 2013
Date Completion: December 2014
Last Updated: October 21, 2014
Last Verified: October 2014