Blog

In recent studies, researchers evaluated vision problems associated with stroke. Last year the European Journal of Neurology published a study evaluating vision issues following an ischemic stroke. Ischemic strokes account for 87% of all strokes in the United States. Some of the more common vision conditions that result from a stroke include: visual field defects, ocular motility difficulties (including oculomotor dysfunction, convergence insufficiency, accommodative dysfunction) visual perceptual difficulties (visual agnosia), and decreased vision. At SUNY State College of Optometry, in New York, researchers evaluated ocular conditions that occur in conjunction with a traumatic brain injury and cerebrovascular accident. Individuals who had a cerebrovascular accident may also have optic atrophy, keratitis, ptosis, and other conditions.

Whether it is a stroke or a traumatic brain injury (TBI), visual changes are likely. Studies have shown that as many as 90% of acquired brain injury patients experience some sort of visual change. Visual changes are so common that it has lead some researchers to conclude that an absence of visual changes would be an exception to the norm and unexpected. Even though visual changes have a tremendous impact of the person's quality of life, many people have a hard time self-identifying vision problems. They often complain vaguely of blurred vision or visual difficulties but cannot articulate what they mean. Vision conditions result in headaches, fatigue, balance difficulties and challenges performing visual-motor tasks throughout the day (such as eating, grooming and other activities of daily living). Unfortunately many of these patients enter into a rehabilitation program or are re-introduced to life without their vision conditions being properly identified – leaving them untreated. It is important to know that there are several visual changes the frequently result from an acquired brain injury. They include:

• Visual Field Defect: Most people are aware of visual field loss following a stroke. The most readily known is a homonymous hemianopia, meaning vision loss in half of the visual field. Visual field defects can affect 20-57% of individuals who have suffered from a stroke. When considering quality of life visual, field defects can inhibit someone from driving or performing other daily activities. The CDC also states that strokes are a leading cause of long-term disability. Researchers are constantly looking at interventions that can help improve health, improve quality of life, and regain patient's independence.

• Ocular Motor Dysfunction: Often referred to as 'difficulties with eye tracking', ocular motor dysfunction can significantly limit one's ability to read, drive, walk, or re-enter the workforce. What makes eye tracking deficits even more complicated is that they can be the direct result of a brain injury, but they can also be the end product of deficits in binocular vision, strabismus or processing deficits. We often see patients who have gone to months of 'tracking' therapy with little progress because the bigger underlying barrier was never identified and thus never treated.

• Binocular Vision Dysfunction: For any individual with two eyes, deficits in eye teaming can result in a number of difficulties. Binocular vision dysfunction can result in headaches, eye strain, fatigue and double vision. The presence of this condition can negatively impact balance, mobility and visual-motor coordination activities. Many acquired brain injury patients give up hobbies, work and driving due to unresolved binocular vision dysfunction.

• Strabismus: Commonly called an 'eye turn', strabismus is common following an acquired brain injury. The eyes can turn in, out, up or down (often a combination). Some cases are quite visible and obvious, others take a trained eye to detect. Whether big or small, a strabismus is a disruption of binocular vision and brings many complications. The presence of strabismus does not mean that surgery is needed. While some people do require corrective surgery, many cases of strabismus in the acquired brain injury population are well managed without the use of surgery.

• Visual Perceptual & Processing Deficits: Visual perception and processing encompass the brain's ability to make sense of visual input. Many people will not seem quite themselves after an acquired brain injury. If they are slower to process information or are confused by visual information they may become lost more easily, be easily distracted, or have a delayed response. Knowing how the brain makes sense of information is just as important as knowing how it takes in visual information.

• Ocular Disease: Dry eye syndrome is commonly associated with acquired brain injury. Dry eye can result in burning/stinging, watering eyes, blurred vision and even double vision. Many people experience fluctuating vision after an acquired brain injury and dry eye is a common contributing factor. In addition to dry eye, acquired brain injury can result in cataracts, optic atrophy, and ptosis.

Individuals who have visual symptoms were more likely to rate their personal health as poor and can suffer from depression. It is important to evaluate every acquired brain injury patient to determine if there are any visual causes that could impact their quality of life. Keep in mind visual symptoms may be very difficult for the patient to articulate and can be missed during a visual screening. The presence of vision conditions will not only limit one's quality of life immediately after the accident, but will also limit success with the rehabilitative process. Without early assessment and intervention from a vision specialist, frustration can arise as progress with rehabilitation is not going as well as expected.

Vision problems often last for months and years after an acquired brain injury – they may never go away. It is important that vision conditions be evaluated by a vision specialist. An optometrist with residency-training in neuro-optometry has the expertise to diagnose and treat your vision conditions following an acquired brain injury. An evaluation by a neuro-optometrist will identify the visual barriers to your success. This allows for targeted treatment of your vision conditions and it allows the doctor to coordinate rehabilitation efforts with the rest of your recovery team. Vision is a dominant sense. Knowing how you use your vision will help your physical therapist, occupational therapist, speech therapist, vestibular therapist, neuropsychologist and managing doctor understand how your vision will limit you during your recovery. More importantly, many of the vision conditions discussed above are treatable. Your neuro-optometrist will design a plan for your recovery, which may include neuro-optometric vision rehabilitation, so that you can start overcoming your visual barriers to success.