Visual dysfunction in veterans after mild traumatic brain injury

Excerpted from page 52 of the April 2017 edition of AOA Focus.

The subject of concussions seems to be everywhere these days, from retired football pros to youth soccer players to veterans returning from combat in the Middle East.

A study published in the journal Optometry and Vision Science examined 500 veterans who experienced a concussion (also known as mild traumatic brain injury, or mTBI) and the ensuing visual disruption that often accompanies head trauma. The purpose was to determine whether there is a difference in symptoms and duration between blast-related trauma from explosives and events such as falls, car accidents or sports concussions.

The brain-eye connection

More than one-third of the veterans in the study suffering from mTBI experienced visual dysfunction. However, the scientists found no difference in symptoms between mTBIs caused by blast events and nonblast events. Additionally, there was no significant difference in symptoms based on the amount of time since the traumatic incident. 

"You don't treat the patient differently if the concussion is from a fall or a blast," says Jason Clopton, O.D., chair of the AOA's Vision Rehabilitation Committee and director of the Center of Vision Development in Cookeville, Tennessee. "You treat the symptomology from it, addressing the underlying neurology and how it is functioning."  

The number of subjects who experience vision dysfunction after mTBI seems to be high in veteran populations. Dr. Clopton thinks the profound and well-documented stress that wartime veterans experience can be a contributing factor.  

"You get issues with people who are under severe stress and have a traumatic injury. Any time you are under stress, your body is going to react less efficiently and less effectively because of the neurotransmitters and hormones going on in your brain," he says. "I see the same thing in abuse situations, with victims in an abusive relationship who have been struck in the head two, three or four times."  

Prescription: Visual rehabilitation

The study concludes that the high number of mTBI victims who suffer from visual dysfunction indicates that military eye care providers need to ensure that veterans have greater access to vision rehabilitation.  

"My experience is that at any point, if a patient has visual symptoms, we can usually improve it with visual rehabilitation," Dr. Clopton says. "I don't think that a lot of our TBIs, especially in the military, are getting the complete picture, because not a lot of people provide vision rehab care. Even if they do, most people provide it as a secondary service or tertiary service where it is just a sideline for them."  

Knowing how to properly diagnose and manage traumatic brain injury (TBI) is increasingly important for doctors of optometry working on multidisciplinary care teams. To help guide these clinical responsibilities and others, use the AOA's Brain Injury Electronic Resource Manual (BIERM).   

Read more about optometry's role in TBI management in the September 2016 edition of AOA Focus.