IU optometrists receive NIH grant to develop eye-movement test to detect sports-related concussions
IU men's and women's sports teams to participate in study
FOR IMMEDIATE RELEASE
BLOOMINGTON, Ind. -- Researchers at Indiana University’s School of Optometry have received a grant from the National Institutes of Health to study mild traumatic brain injury in Indiana University and high school athletes. The two-year, $429,000 grant will specifically fund development of a portable sideline eye tracker that can be used to test eye movements of athletes during competition as a possible biomarker for the injuries.
The NIH estimates there are 3.2 million cases of mild traumatic brain injury in the U.S. annually, 1.5 million of those being sports-related and 25,000 of those in high school athletes.
The researchers -- assistant professor Nicholas Port and clinical associate professor Steven A. Hitzeman -- in collaboration with IU team trainers and physicians have been conducting pilot projects over the past four years, primarily with athletes on the IU men’s football and soccer teams and the women’s soccer team. The new funding will allow them to expand the research to also include men’s basketball, wrestling and baseball, women’s basketball, volleyball, softball and field hockey, and male and female cheerleaders. The team also plans to work with some area high school sports programs.
The grant also funds two athletic trainers who will work for the researchers but assist team trainers.
“The idea is to develop and test an eye tracker that will be used on the sidelines in broad daylight or at night and that will be self-contained inside a pair of virtual reality goggles,” Port said. “Based on a body of research documenting performance of eye movements -- such as saccades and smooth pursuit -- in relation to mild traumatic brain injury, we successfully proposed building a sideline eye tracker and to evaluate its clinical utility as a rapid, objective and accurate test for sports-related concussions.
“We are trying to build an automated, objective tool for concussions that is analogous to the blood pressure cuff or breathalyzer,” Port said.
Saccades are the quick, rapid and jerk-like eye movements we use for scanning the world, while smooth pursuit eye movements require a smoothly moving stimulus, like watching a sporting event.
Improvements are needed in testing for sports concussions because the current test is neuropsychological and requires 30 minutes in a controlled testing environment. It has also been shown to be susceptible to a subject’s motivational factors.
The researchers will conduct a double case-controlled, longitudinal comparison of 60 concussed athletes, 60 matched non-concussed athlete controls, and 60 matched non-athlete controls over two seasons of athletic play. They will examine all three groups for ocularmotor performance using the new sideline eye tracker and the currently used neuropsychological test, with both groups of athletes tested at baseline (pre-injury), post-injury and post-season, and the non-athletes tested at baseline and post-season.
Port, the principal investigator on the grant, said the involuntary nature of eye movements could serve as the perfect avenue for developing an ideal assessment tool for minor traumatic brain injuries. Such a tool would need to evaluate an aspect of brain function that involves a broad range of structures (subcortical, cortical and cerebellar) so that diffuse, low-level damage can be detected. The tests must also be conducted quickly within a short time frame and at a reasonable cost, be transportable and make it difficult for subjects to manipulate results.
“Our eye movements are under limited voluntary control,” he said. “For saccades, or quick scanning, we can choose where to look next but not how the eye gets there. Unlike choosing to move an arm quickly or slowly, eye kinematics are driven involuntarily by the brain stem.”
Similarly, lag time in smooth pursuit movements -- keeping up with or falling behind a target -- are involuntary and linked to the velocity of the stimulus, and ocular following is a machine-like involuntary reflex, Port added.
“In short, motivation plays no role in eye kinematics, and they cannot be faked. Dysfunction is a sign of neurological injury,” he said.
Port and Hitzeman are working with the Indiana University Research and Technology Corp., an affiliate of IU that manages commercialization of IU’s intellectual property, to protect the intellectual property rights in the eye tracker, and IURTC has filed a patent application.
“Mild traumatic brain injury is a serious problem affecting athletes of all ages in numerous sports, and IURTC is excited to be working with the inventors to develop and commercialize this new diagnostic tool,” said Bill Brizzard, director of technology commercialization for IURTC.