Oculomotor assessments
Increasing amounts of research over the last decade indicate that visual tracking is a sensitive tool for diagnosing and assessing brain function, and in particular, concussion. The rationale for using eye-tracking as a measurement relies on the fact that specific eye movements originate from distinct regions of the brain, therefore also enabling interpretation about brain region function.
There are several types of eye movements that are of interest to the assessor. These include:
- Saccades: quickly moving the eye from one target to another
- Pursuits: tracking a target as it is moving
- Fixation stability : fixating the gaze on a stationary target
It should be noted that the motion of the eye is different to clarity of image. Motion is controlled by the 6 muscles behind the eye, which in turn are controlled by certain parts of the brain, whereas visual acuity relates the clarity of the image as it is focused on the retina.
The accuracy and quality of eye movements is measured by an infrared camera which accurately determines the pupil of the eye. The motion is then given as data, such as tracking accuracy, errors and speed, so that meaningful information can be compared to age-related normal values, or previous tests.
Despite eye movement being such a useful insight into brain function, it is largely underutilised. A 2019 article in the Royal Australian Journal of General Practice states that “Ocular dysfunction, including eye movement defects, has been documented in up to 69% of patients with concussion. However, standard sports-related concussion assessment protocols do not typically include any clinical examination of the ocular system.”
Watch the video below to see a demonstration of eye-tracking technology.
