“What’s today’s date? What were you doing when you hit your head? Follow my pen with your eyes.”
These are all things a doctor might say during an examination to diagnose concussion—a process that can seem more of an art than a science.
“Concussion is a three-legged stool. When you get assessed, you get assessed for eye movement—'follow the tip of my finger’—and you get assessed for cognitive and memory issues. You also get assessed for balance,” said Melissa Hunfalvay, co-founder and chief science officer at RightEye, a company that markets eye-tracking tests to improve vision performance.
The Bethesda, Maryland-based company offers several tests using its EyeQ technology that is FDA-cleared for “recording viewing and analyzing eye movements in support of identifying visual tracking impairment in patients.” The tests are not approved for clinical applications and rather are aimed at improving brain health, reading and functional vision. But a new study suggests it could provide doctors an objective and quantifiable way to diagnose concussion.
Investigators recruited 195 people who had suffered a traumatic brain injury (TBI) within a month of the study as well as people with no history of TBI. The patients had injuries of varying severities: 64 were mild, 57 were moderate and 23 were severe. Their injuries were diagnosed by a neurologist or neuro-optometrist.
The patients each did two tests to assess saccade, one of the three types of eye movements. Unlike fixation, which requires a person to keep their eyes still, and pursuit, which involves following an object, saccade is a fast movement that reorients the eye to an area of interest, Hunfalvay told FierceBiotech.
“That really came from our evolution, if you think about us trying to decide if something is a predator or prey,” said Hunfalvay, who co-authored the study.
The tests had patients move their eyes back and forth between two dots as quickly and accurately as possible. They assessed the patients’ ability to move their eyes up and down and from side to side. The study, published in the journal Concussion, found that the horizontal saccade test correctly identified people with concussion 77% of the time and the vertical saccade test did so 64% of the time. They were equally accurate at identifying patients without an injury.
“The study found that functional vision tests using RightEye’s eye-tracking technology are a useful, precise and objective measure of underlying neurological health that indicates the presence of TBIs,” RightEye said in a statement. The company is working on a study that tests a different eye movement.
In addition to providing precise measurements, the EyeQ technology addresses the binary result of “follow-my-finger” screens—that is, the patient followed the finger, or they didn't.
“You can’t really measure how fast a person moves their eyes by looking at them,” Hunfalvay said. What’s more, it’s difficult to tell whether a patient is actually looking at the tip of a finger, or if they have actually overshot it or stopped short, she said.
Because the EyeQ system precisely picks up small, quick movements, it may be able to differentiate between mild, moderate and severe concussions. It also quantifies a patient’s performance on a scale of zero to 100, providing a baseline heading into treatment and a way to measure improvement as a patient progresses.
“Concussions remain one of the most difficult neurological issues to detect and accurately diagnose,” said Mark Baron, M.D., a neurologist at the Virginia Commonwealth University, in the statement. “Sadly, a significant percent of patients who have sustained a mild injury go undiagnosed. Having a tool that allows doctors to quickly and objectively analyze the neurological health of people could help uncover countless hidden concussions and empower doctors to create tailored treatment plans in line with the severity of the injury. Critically, having rapid access to quantifiable eye-tracking data about the neurological health of people will allow doctors to precisely monitor treatment progress and confidently approve individuals to return to their normal activities."