As concussion awareness rises, more parents and sport teams are doing baseline concussion screening. Many of these tests include balance and/or cognitive testing. Only some of them include eye test screening as well.
A brain injury is often only identified when moderate or severe head injuries have occurred, leaving mild cases undiagnosed and untreated. A mild head injury accounts for approximately 80% of reported trauma brain injury according to US department of defense statistics. That’s why it is important to develop simple tests that can identify mild cases. Tests that can also be done on field as well.
4 simple eye tests have been used by José Capó-Aponte, OD, PhD, from the Department of Optometry at the Womack Army Medical Center in Fort Bragg, North Carolina, as an effective screening tool for acute mild traumatic brain injury.
“Since approximately 30 areas of the brain and seven of the 12 cranial nerves deal with vision, it is not unexpected that the patient with traumatic brain injury may manifest a host of visual problems, such as papillary deficit, visual processing delays, and impaired oculomotor tracking and related oculomotor-based reading dysfunctions,” Dr Capó-Aponte pointed out.
The following tests were used by Dr Capó-Aponte and his team to identify reliable biomarkers of mild traumatic brain injury. The team looked for subtle visual changes that could be measured in the office or in the field.
- Testing Pupil using a monocular infrared pupillometry:
- near-point convergence
- saccadic eye movement function with the King–Devick Test
- Visual symptoms were assessed with the Convergence Insufficiency Symptom Survey (CISS).
These tests are used because patients with mild traumatic brain injury had significantly higher near-point convergence scores (receded near-point convergence) than control subjects, longer times to complete the King–Devick Test, and more symptoms on the CISS. The pupil test also revealed that average constriction velocity, average dilation velocity and time to 75% recovery of dilation were significantly different between mild traumatic brain injury and control subject.