Investigating the Eye’s Role in Concussions

Jan 12, 2016 at 12:42 pm by steve


In recent years, much attention has been given to new ways of testing for concussion injuries. However, diagnosis and monitoring of these mild traumatic brain injuries (mTBI) can be hindered by the absence of reliable biomarkers and are difficult to pinpoint with standard CT and MRI testing. New diagnostics and therapies for the vestibular and oculomotor systems, currently being tested at UAB, may provide medical personnel the answers they need.

A group of clinician-scientists from UAB Optometry and UAB Physical Therapy determined from growing literature that the vision and vestibular systems may be a link to many of the symptoms related to mTBI. In partnership with Children’s of Alabama, they established the Vestibular and Oculo-motor Research (VOR) Clinic at UAB where they can evaluate young athletes who have suffered concussions.

“A person’s vestibular-oculo reflex system works to keep vision clear while the body is in motion. The system uses accelerometric sensors located in the inner ear to control body balance and to stabilize – using eye movements – the retinal images of the surrounding visual environment while the head is in motion,” says Katherine K. Weise, OD, MBA, a pediatric optometrist at UAB. “Concussion literature shows that these patients typically have tracking issues, problems pointing their eyes toward the same place on a page, and crossing their eyes, which we call convergence. Testing showed that convergence insufficiency was prevalent in these patients.”

In their Convergence Insufficiency Treatment Trial, the researchers studied healthy children with convergence insufficiency for 16 weeks with standard vision rehabilitation training. The results, published in 2008, showed a 73 percent improvement as a result of the vision rehab. “This was a rigorous scientific study funded by the National Institutes of Health,” Weise says. “We use the results to conduct evidence-based eye exercises in our rehab program, and we hope to put it to good use in impact exposure research.”

Their research hypothesis is that in the case of concussion, the vestibular ocular reflex system is not functioning correctly and is causing the swimming feeling in the head, dizziness, headaches and eye tracking issues. A recent grant enabled the team to purchase a state-of-the-art rotational chair with video tracking of eye movements to test eye tracking, as well as balance and the function of saccles and utricles. The rotational chair is used in addition to ENG/VNG (caloric) testing to confirm a diagnosis and to increase diagnostic accuracy. This allows a physician to see what head movement speeds are affected by inner ear disturbances and ensures an accurate diagnosis specific to a problem within the vestibular system. A third piece to the VOR Clinic is the NeurOPtics pupilometer which allows clinicians to evaluate pupil light reflex in clinics and on sports fields.

“Our chair is the only one in the state available to civilians. There is another one at Ft. Rucker,” Weise says. “We purchased the same chair that they have at Ft. Rucker in the event that we wanted to broaden our research to include blast-injury concussion. A collaboration like the one between Children’s of Alabama and UAB scientists, clinicians and athletes can be found nowhere else in the country on a single campus.”

Those working with Weise on the project include James Johnston, MD, UAB Neurosurgery; Jennifer B. Christy, PT, PhD, UAB vestibular science; Matthew Heath Hale, MPH, MD, Children’s of Alabama Concussion Clinic and UAB team physician; Claudio Busettini, PHD (UAB Vision Science; Mark Swanson, OD, MSPH, UAB adult eye care; Joseph Ackerson, PhD, neuropsychology; and Christopher Mike Jones, MAE, UAB Football head athletic trainer. The team of researchers currently are working on three proposals to present for grants that would enable them to continue their work in the VOR Clinic.

First, they want to examine athletes during their high school years to determine the effects of cumulative impacts on the brain. “This is not just about concussions. We want to see what happens to their eye movements over time if they play sports which include football; other impact sports like soccer or rugby; and a control group of non-impact sports like cross country and swimming,” Weise says. “We hope to compare the three groups in the rotational chair and get results that will help us develop a diagnostic tool that would be available to physicians in small towns everywhere.”

Another grant proposal is the examination of convergence insufficiency and concussion. The UAB and Children’s of Alabama team would partner with Children’s of Philadelphia and Children’s of Orange County in Los Angeles to test the 16 weeks of vision rehab against placebo exercises on concussed children to determine if the training speeds speed up recovery.

A final proposal study will try to find correlations between the eye and the brain. If this request is approved, the researchers will work with football players from UAB and other universities from sophomore to senior year to determine the effect of impact exposure on eye and brain function over the course of three years.

While waiting for the larger grants to be approved, Weise and her team continue to work with children and student athletes to determine how the eye can help identify concussions. Even without the money, they plan to continue their search for answers that will help these young patients.

“None of us is motivated by money. The best case scenario is that we help children,” Weise says. “We want to have many kids playing football and doing it safely. If we can combine engineering, science, medicine, optometry and athletics and use the evidence to make our sports safer, we are all happy.”

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