New Technology Advances Eye Tracking As Biomarker For Brain Function And Brain Injury

A veteran with a small skull fracture and bleeding on the surface of his brain had eye movements that were most intensely affected prior to surgery for repair (day 0). Vertical movements were decreased relative to horizontal movement. As the patient recovered over the next several weeks the eye movements gradually returned to near normal (day 35).
A veteran with a small skull fracture and bleeding on the surface
of his brain had eye movements that were most intensely affected
 prior to surgery for repair (day 0). Vertical movements were
decreased relative to horizontal movement. As the patient
recovered over the next several weeks the eye movements
gradually returned to near normal (day 35). (Credit: NYU
Langone Medical Caneter)
Researchers have developed new technology that can assess the location and impact of a brain injury merely by tracking the eye movements of patients as they watch music videos for less than four minutes, according to a study published in the Journal of Neurosurgery. The study suggests that the use of eye tracking technology may be a potential biological marker for assessing brain function and monitoring recovery for patients with brain injuries.
 
The study looked at 169 veterans; 157 of whom were neurologically healthy and 12 who either had known weaknesses in the nerves that move the eyes, or brain swelling adjacent to those nerves. These nerves affect how the eye moves up and down and side to side.
 
Using a technology developed at NYU Langone, the investigators had the participants watch a music video or television content for 220 seconds while they measured the ratio of horizontal to vertical eye movements. They discovered that in the neurologically healthy subjects, the ratios were close to one-to-one, with horizontal movements equaling vertical movements. But the 12 participants with nerve damage or swelling in the brain pressing on nerves all showed abnormal eye movement ratios correlating to the nerve that was affected. In every case where the abnormal eye movement was due to swelling in the brain, surgery to fix the brain problem also restored the eye movements to normal range.
 
The findings offers a proof of concept that this technology can detect brain injury and suggest its location. One of the reasons that clinical trials for treatment of brain injury have failed in the past is that brain injury is hard to classify and quantitate with existing technologies. This invention suggests a potential new method for classifying and quantitating the extent of injury. Once validated, it will both accelerate diagnosis and aid in the development of better treatments.
 
Brain injury is the number one cause of death and disability in Americans under age 35,   according to the U.S. Centers for Disease Control and Prevention. Every year, 1.4 million people suffer from a traumatic brain injury in the United States. Of those, 50,000 die and 235,000 require hospital admission.