The term acquired brain injury (ABI) refers to traumatic brain injuries (TBI) and cerebral vascular accidents (CVA), or stroke.åÊ Each year an estimated 8 million people will suffer a traumatic brain injury and 500,000 will suffer a CVA.åÊ According to a study conducted through the State University of New York State College of Optometry and the Raymond J. Greenwald Rehabilitation Center in New York, the majority of all ABI patients will develop some degree of an oculomotor dysfunction.
The five areas of oculomotor dysfunction researched in this study were accommodation, version, vergence, strabismus and cranial nerve palsy.åÊ Although all ABIs are unique to the individual, certain oculomotor dysfunctions were found to be more prevalent given the type of ABI.åÊ The following statistics represent the trends found through this particular study.
- More than 40% of the TBI patients demonstrated an accommodative dysfunction while the amount of CVA patients with this deficit was only 12.5%.
- Convergence insufficiency was found to be the most frequent vergence dysfunction in both the TBI and CVA patients.
- Nystagmus, a version oculomotor dysfunction, was 30 times more prevalent in the CVA subgroup in comparison to the TBI patients.
- Approximately one fourth of TBI patients and 37% of CVA patients had acquired some form of strabismus.
- Ten percent of CVA patients had a cranial nerve palsy, primarily 3rd nerve palsies, while 7% of TBI patients had a cranial nerve palsy, primarily 3rd and 4th nerve palsies.
The study indicates that 90% of the TBI patients and 86.7% of the CVA patients manifest some form of oculomotor dysfunction.åÊ Based on these significant statistics, it’s imperative that these patients receive a comprehensive eye examination to adequately address any underlying binocular vision problem that may exist.åÊ Each ABI case must be addressed on an individual basis, however there are certain trends that one should be aware of when determining the appropriate treatment plan for these patients.
To learn more about brain injuries and the effects they may have on the visual system, follow the links below.
Lindsey Stull, O.D.