Vision Problems After Traumatic or Acquired Brain Injury

Vision Therapy for Traumatic Brain InjuryCurrent research indicates that approximately 80% of patients that suffer from a traumatic brain injury are struggling with vision deficits which are a direct result of their injury. There are a myriad of types of brain injuries that can result in visual disturbances including:

• strokes
• motor vehicle accidents
• concussions/whiplash injuries
• status-post neurosurgery for tumor resection or aneurism repairs

Vision deficits are also extremely common in individuals struggling with Parkinson’s disease, myasthenia gravis and multiple sclerosis.

20/20 Is Not Enough

It is important to note that even if a patient passes the standard basic vision exam with “20/20", it is still possible to have difficulty with visual function.  This is because 20/20 does not mean perfect vision or normal vision, as most of the general public believes. “20/20” is a measure of only ONE visual function, (known as visual acuity), which measures the eye’s ability to resolve visual detail at a distance of twenty feet. Although seeing clearly in the distance is certainly important, there are a host of other visual functions aside from visual acuity that must function optimally, in order to say whether an individual has a properly functioning vision system.

Comprehensive Vision Rehabilitation Evaluation

Symptom Checklist for Post Trauma Vision Problems

Comprehensive vision rehabilitation evaluations are different from basic eye examinations, as they will test ALL of the vision skills that are required for optimal visual function. Vision rehabilitation evaluations will test visual acuity (20/20) and the health of the eyes, but they also evaluate many other areas as well.

Optometrists specializing in vision rehabilitation perform additional tests of:

• visual tracking
• binocular vision and depth perception
• accommodation (focus)
• peripheral vision
• and visual perceptual functions.

If visual deficits exist in these areas, it can result in significant difficulty with reading, mobility and balance, and prevent individuals from functioning independently and returning to their routine activities and careers.

Common vision disorders that occur after brain trauma are:

Double Vision

Double vision is a frequent complaint of patients who have experienced a head trauma, and results when the two eyes deviate, and do not align to the same point in space.

A cosmetic eye deviation (known as strabismus) may be clearly visible in some patients, with one or both of the eyes deviating either in (esotropia), out (exotropia) or up/down (hypertropia).

In many cases however, an eye deviation may not necessarily be visible, (even with a report of double vision), because the eye deviation may in fact be quite small. Some patients struggle with specific types of eye deviations like cranial nerve palsies of the 3rd, 4th or 6th oculomotor nerves, creating double vision which increases in different positions of gaze.

Double vision is extremely disorienting, and as a result can create:

• dizziness
• balance difficulty
• difficulty walking
• difficulty reading
• difficulty performing many other activities of daily living

Double vision impairs the ability to perceive depth (or 3-dimensional vision) and also results in deficits in eye-hand coordination. Patients may appear increasingly clumsy, spill things often or knock things over, or have difficulty walking up or down stairs.

Double vision in patients with head injury should be treated right away.

Resolving these visual deficits will not only help the patient feel better visually, but will have a significant effect on their ability to progress within the other therapies these individuals are often receiving (ie. occupational, physical, cognitive and speech therapies).

Many doctors will simply give the patient an eye patch, which is unsightly and does not restore normal binocular vision. Treatment of double vision however should include one or a combination of therapies including fresnel (plastic) or ground-in prism compensation in lenses, or vision rehabilitation therapy to restore binocular vision and improve depth perception.

A thorough vision rehabilitation evaluation by a professional specializing in this area, will indicate which treatment option is indicated.

Visual Field Defects

Loss of peripheral vision is a frequent result of many head injuries. Visual field loss on the left is common after suffering a stroke on the right side of the brain. Conversely, visual field loss on the right is common after suffering a stroke on the left side of the brain. Peripheral visual field loss is also common after neurosurgery to remove tumors or after aneurysm repairs.

Peripheral vision loss can be very disorienting, and patients often may exhibit symptoms of difficulty seeing things off to one side, they may bump into things when walking, and also have difficulty reading along lines of print. Mobility and balance are often significantly effected.

Treating Visual Field Defects

Specialized prism lenses can have significant value in helping patients with visual field deficits. Although prism lenses do not restore peripheral vision, they allow many patients to function more easily, so that they have greater awareness of the effected visual field, they do not bump into things, and allows for easier reading. Vision rehabilitation therapy is also extremely effective in developing improved scanning strategies, so that patients may function more easily and independently.

Visual Scanning or Tracking Problems

Disorders of eye movements are another frequent result of acquired brain injury. Pursuits (the ability to follow a moving target) and/or saccades (the ability to scan from one point to another)very often become “jerky”and unstable.

Poor eye movements can result in difficulty scanning along lines of print or when trying to read, and can also interfere with writing along lines accurately.

Nystagmus is a particular type of eye movement deficit, which will often create significant symptoms of imbalance and dizziness. The brain will frequently interpret the world as if it was moving, (known as oscillopsia), because of this newly acquired, involuntary, oculomotor deficit.

Nystagmus may be clearly visible to the naked eye, or it may be harder to see - only being detected though an examination.

Treatment

Treatment includes an assessment of whether or not there is a particular position of gaze where the nystagmus reduces. If this is seen, specialized lenses may be prescribed incorporating yoked prism, allowing for improved head/body posturingand ultimately improved balance.

Additionally, various types of occlusion are also very often effective in reducing the symptoms associated with nystagmus. Finally, vision rehabilitation therapy to improve eye movement control and to teach compensatory strategies, may also be indicated for particular patients.

Disorders of Binocular Eye Coordination or Focus

Convergence insufficiency (the inability to bring the two eyes together at near range) is the most common type of binocular vision deficit which is seen in head trauma. Accommodation (focusing) deficits are also extremely common in young adults and children suffering from head injury.

These visual disorders can create symptoms of:

• words appearing to move or jump on the page
• blurred vision
• double vision
• eyestrain
• headaches
• motion sickness
• difficulty concentrating on reading, computers or other tasks close up
• disorientation
• dizziness

Treatment will consist of vision rehabilitation therapy. Reading lenses and/or prisms may also have great value for in certain cases.

Acquired visual perceptual deficits

Vision involves more than merely seeing images on our retinas. Information is sent to the visual cortex, where sensory information is interpreted and processed so that we can understand and make sense out of visual information that is presented.

Many patients develop acquired visual perceptual deficits as the result of head injuries, which can create visual confusion and difficulty understanding visual information.

Reading comprehension is often affected, patients have difficulty remembering things they see, they might forget where they put things, have difficulty navigating, or again have difficulty organizing their activities throughout the day. Vision rehabilitation therapy can be very beneficial for patients with acquired visual processing deficits.

In conclusion, a thorough vision rehabilitation evaluation is extremely valuable for patients struggling with the aftermath of a traumatic head injury. Vision deficits are extremely common in this population, and treating them will have a significant impact on resolving patient symptoms and will help patients return to more independent lives as quickly as possible.

Vision and Brain Injury Checklist

Do You or A Loved One Have Any of these Vision Symptoms as the Result of A Brain Injury?

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