| Sumario: | Background: Issues with light sensitivity, especially photophobia, may be reported by nearly half of Veterans with a history of traumatic brain injury (TBI). We designed our innovative approach, known as Averted Vision Training (AVT), to help patients find their way to optimal patterns of fixation that may lead to improvement. Averted vision refers to looking off-center to see faint objects when the eyes are dark adapted, such as viewing a dim star in the night sky. Methods: The study has a mixed-methods design that includes two questionnaires, tests for visual evoked potentials (VEP), and functional assessments with standard contrast sensitivity charts and a microperimeter. Results: Four Veterans with comorbid history of mild or moderate TBI and post-traumatic stress disorder who complained of light sensitivity completed the study. Each was characterized with evidence of brain injury by VEP testing and reported subjective improvement in light sensitivity in response to the training. In exploring microperimetry for objective measure, we found that results for threshold sensitivity were inconclusive, yet results for fixation area were promising. A significant change (enlargement) in the mean fixation area from baseline to posttreatment yielded a large effect size of 1.67, with 55% of the variation attributed to subject performance. These results are suggestive for the use of fixation area as an outcome measure in the rehabilitation of patients with complaints of light sensitivity. Conclusion: As an addition to the basic science of the visual effects of TBI, the potential of having a change in fixation area in response to AVT as an additional valid repeatable testing modality is a substantial strength. If evaluation is left to traditional clinical tests of fixation and light sensitivity, then the opportunity to identify and benefit these Veterans may be missed.
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