Abstract
Purpose :
Objective: At present, there is no objective vision biomarker for human photosensitivity (PS). Thus, the present study sought to find potential objective biomarkers for PS within the pupillary light reflex (PLR). A descriptive quantitative research design was employed whereby differences in dynamic pupillometry in those with and without PS in those with and without a history of mild traumatic brain injury (mTBI) were investigated.
Methods :
Methods: The pupillary light reflex (PLR) was evaluated in mTBI and in normal individuals with and without PS under a range of test conditions. The Neuroptics DP-2000, infrared, binocular pupillometer was used with binocular stimulation and recording. Twelve pupil parameters and 6 stimulus conditions (pulse, step; red, blue, white light) were quantitatively assessed in 32 adults (18-60 years old) with mTBI and compared to 40 gender and age-matched normals.
Results :
Results: Normal subjects with PS had four significant differences (t-test) (p < 0.05) as compared with their non-PS cohort: larger constriction amplitude, faster average constriction velocity, faster peak constriction velocity, and slower recovery time (i.e., re-dilation). mTBI subjects with PS had six significant differences (t-test) (p < 0.05) as compared with their non-PS cohort: larger baseline diameter, larger minimum diameter, faster peak dilation velocity, faster recovery times, and a larger pupil diameter at 6 seconds post-stimulus under the bright blue light condition.
Conclusions :
Discussion: Several dynamic pupillometry parameters were significantly different in those with and without PS in both the mTBI and normal groups. These specific parameters could serve as potential, objectively-based biomarkers for photosensitivity in the populations tested.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.