Eye Movement Disorder Following Brain Injury

Oculomotor Dysfunction is a relatively common vision problem, occurring in both children and adults. Oculomotor Dysfunction is a visual condition sometimes referred to as 'tracking difficulties' or 'eye movement disorder'. Oculomotor dysfunction commonly results from an acquired brain injury and can have profound impacts on a person's quality of life.

Oculomotor Dysfunction (OMD) is often times associated with reading difficulties because the eyes do not move as accurately as they should, nor as quickly as they should from left to right across a line of text, nor effortlessly from one sentence to the next. OMD can also make it difficult to scan one's visual environment – which can negatively impact mobility or driving.

As mentioned, Oculomotor Dysfunction is a fairly common vision problem among the general population. However, among patients who have suffered an acquired brain injury the occurrence of Oculomotor Dysfunction is staggering. Acquired brain injury (ABI) includes both traumatic brain injury (TBI) and cerebrovascular accident (CVA), commonly referred to as stroke. Studies show that 90% of all traumatic brain injury patients and 86.7% of all stroke patients experience vision problems classified as Oculomotor Dysfunction.

• Approximately 8 million people per year in the United States suffer a traumatic brain injury

• 1.5 million of these injuries are categorized as “major”

• Close to 60% of those affected do not return to the workforce

• Traumatic brain injury is a contributing factor to one-third of all injury related deaths in the United States

• Traumatic brain injury can increase the risk for epilepsy, Alzheimer's disease and Parkinson's disease

• Stroke is the leading cause of chronic disability, affecting 500,000 people per year

It is not surprising that following an acquired brain injury, the majority of patients experience deficits with the visual system. Over 50% of the brain is directly or indirectly involved with the visual processes. The visual dysfunctions following an acquired brain injury include:

• Oculomotor Dysfunction

• Binocular Dysfunctions

• Visual field deficits

• Reduced visual acuity

• Reduced color vision sensitivity

Among acquired brain injury (ABI) patients, the majority experience Oculomotor Dysfunction, binocular vision deficits, visual field defects or a combination of these conditions. These conditions can slow or prevent progress in rehabilitative therapies, affect the stability of recovery, and impact long-term quality of life.

Among traumatic brain injury (TBI) patients, convergence insufficiency was found to be about 40%, cranial nerve (CN) palsy was 33%, and accommodative dysfunction about 20%.

Among cerebrovascular accident (CVA) patients, as many as 86.7% experience some type of Oculomotor Dysfunction, strabismus approximately 36.7% and cerebral nerve (CN) palsy about 10%.

The eye care community has known for decades that acquired brain injuries affect the visual system, however assessment of Oculomotor Dysfunction, eye teaming, and eye focusing are not evaluated by every eye care provider. A comprehensive neuro-optometric, functional vision examination should be recommended for all acquired brain injury patients as visual dysfunctions post acquired brain injury are common. The timing and coordination of this specialized vision examination is dependent upon the stability of the patient.

Following a neurological event, such as an acquired brain injury, cerebrovascular event (stroke), multiple sclerosis, etc. the immediate medical needs of the patient must be attended to. As the survival needs of the patient are met, a multi-disciplinary care and rehabilitation team will be established. The rehabilitation team may include a physiatrist or case manager, physician, neuro-optometrist, physical therapist, occupational therapist, speech therapist, psychologist, and vocational specialist. The physiatrist, or case manager, is an integral member of the rehabilitation team and is responsible for overseeing and coordinating care.

The physiatrist must be aware of the effects of a visual system deficit and the potential negative affects on rehabilitation outcomes if the visual dysfunction is not diagnosed and properly treated. Unfortunately the vision problems that occur following a neurological event often times remain undiagnosed following a routine vision examination; accurate diagnosis and treatment requires a comprehensive neuro-optometric, functional vision examination by a residency trained neuro-optometrist.

Confusion regarding vision care among physiatrists, therapists and members of the general public leads to the lack of identification and diagnosis of vision problems, and subsequent treatment. This is unfortunate because vision is required for most rehabilitation activities with physical therapists, occupational therapists, etc. Vision deficits, and in particular oculomotor deficits, negatively affect the overall progress and outcome of rehabilitation therapies.

The majority of brain injury rehabilitation therapies involve the visual system. Saccadic visual search and visual scanning activities are used in cognitive rehabilitation as well as speech / language rehabilitation. Vergence and accommodation are used during vestibular rehabilitation. Within the medical community, it is acknowledged and well accepted that Oculomotor Dysfunction adversely affects the progress and ultimate outcome of brain injury rehabilitation.

Additionally, current research shows that optometric vision therapy can be an important treatment modality in the vision rehabilitation for those with an acquired brain injury who are experiencing Oculomotor Dysfunction. Treatment of Oculomotor Dysfunction and the improvement of oculomotor deficits have shown to positively impact the overall rehabilitative progress; including physical therapy, occupational therapy, etc.

The first step in successfully managing the visual effects of your acquired brain injury is to make sure the acquired brain injury patient is evaluated by a doctor who is familiar with the visual repercussions of an acquired brain injury. At Advanced Vision Therapy Center we recommend that acquired brain injury patients be evaluated by Dr. Ryan Johnson. Dr. Johnson completed his residency training in neuro-optometry, binocular vision, and vision therapy at the University of California, Berkeley. He has both the knowledge and experience to diagnose and treat the visual conditions caused by an acquired brain injury.