Among patients presenting with dizziness, visual dysfunction must be considered, including vertical heterophoria (VH), a frequently under-identified form of binocular vision dysfunction where there is vertical discrepancy between the lines of sight of the eyes when at physiologic rest. Current self-rated screening measures do not account for complex VH symptomatology including dizziness/ambulation difficulties, nausea, headache, anxiety, neck pain, and reading impairment. VH must be differentiated from vestibular/otolithic etiologies, as their treatment frequently provides inadequate relief, yet treatment of the VH can reduce/eliminate symptoms. The objective of this study is to create a valid measurement tool (binocular vision dysfunction questionnaire) to assist in identifying VH among dizzy patients to aid in appropriate referral.
Study Design: Retrospective case series.
Setting: Tertiary referral center.
Patients: One hundred twenty-six patients presenting to an optometric binocular vision subspecialist diagnosed with VH.
Intervention: Psychometric study. The measurement tool’s internal consistency and test–retest reliability was assessed.
When a concussion occurs, diffuse damage is done to the brain. Any part of the brain can be injured, which is why there are so many different types of symptoms associated with concussions. One part of the brain that is frequently injured is the visual system, resulting in Binocular Vision Dysfunction (BVD), where the two eyes have difficulty working smoothly together as a team due to a slight misalignment. While this misalignment can be very subtle, it can make it incredibly difficult for our eyes to send one clear image to our brain.
In patients with BVD, there is a slight misalignment between their eyes resulting in their eyes being out of sync with one another, causing the brain to have a very difficult time processing those two separate images to form one clear image.
The result? The brain forces the eye aligning muscles to fix the problem by realigning the eyes. But the realignment is only temporary and misalignment then recurs, which is followed closely by realignment, and the cycle of misalignment and realignment continues. Over time, this places an immense amount of strain on the eye muscles and leads to dizziness and difficulty reading, as well as a variety of other symptoms.