For parents, family members, and friends, there is no more terrifying sight during a sporting event than seeing a loved one collapse on the court or field in pain after head-to-head contact. Concussions, a form of mild traumatic brain injury (mTBI), can disrupt the intricate communication pathways between the brain and the visual system. Athletes, especially those in contact sports, are at a heightened risk of concussions, and the impact can extend far beyond the playing field, affecting their long-term cognitive and visual health.

Concussions in athletes are a significant, omnipresent concern with both short- and long-term health risks. In April, as we acknowledge Eye Sports Safety Month, we also reflect on the neurological risks athletes face and eye care practitioners' role in diagnosing concussions and being part of athletes' comprehensive care team.

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The Prevalence of Concussions in Athletes

Concussions are all too common in athletic competition. According to the University of Michigan Health, an estimated 1.6 to 3.8 million athletes experience concussions annually in the U.S. from sports-related injuries. Contact sports like football, hockey, soccer, and basketball have a particularly high incidence of head trauma. However, concussions can occur in any sport or recreational activity.

One of the greatest challenges with treating and caring for injured athletes is the prevalence of underreporting concussions. The National Institute of Health (NIH) reports that nearly one-third of athletes have sustained a blow to the head that resulted in the signs and symptoms of a concussion but was not diagnosed as a concussion. Failure to diagnose concussions in athletes can lead to further, potentially devastating injuries to the brain. This dangerous phenomenon occurs when competitors — across all ages, from recreational leagues to professional athletes — downplay symptoms to continue playing or because their symptoms are subtle and they don’t realize they have suffered serious trauma. 

Long-Term Risks of Undiagnosed Concussions

Undiagnosed and untreated concussions can have serious long-term consequences, including:

• Post-Concussion Syndrome (PCS)- Persistent symptoms like headaches, dizziness, fatigue, cognitive difficulties, and mood changes that can last for weeks, months, or even years.
• Second Impact Syndrome (SIS) - A rare but potentially fatal condition that can lead to rapid brain swelling and death. It occurs when a second concussion happens before the first one has fully healed.
• Chronic Traumatic Encephalopathy (CTE) - A progressive degenerative brain disease associated with repetitive head trauma, including concussions. CTE can cause cognitive decline, mood disorders, and behavioral changes.

Concussions can also lead to vision problems. In the short term, these issues include:

• Blurred or double vision - This symptom can occur due to damage to the muscles and/or nerves around the eyes or the brain's visual processing centers. 
• Light sensitivity (photophobia) - Many people experience increased sensitivity to light after a concussion. 
• Difficulty with eye movements -  Concussions can disrupt the coordination of eye movements, leading to problems with focusing, tracking, and reading. 
• Eye pain - Some individuals may experience eye pain or headaches following a concussion.
• Visual motion sensitivity - This can cause dizziness or difficulty with balance. 
• Scotomas: Small blind spots can appear, disrupting visual clarity and potentially affecting depth perception. Concussion-related scotomas may also be permanent.

• Peripheral vision loss: Athletes may experience narrowed visual fields, impacting their spatial awareness and reaction time. Peripheral vision loss may also become permanent.

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In some cases, vision problems can persist for several months or even years after a concussion, especially in individuals with severe injuries or multiple concussions. Long-term vision problems caused by concussions may include:

• Changes in focusing, eye teaming, depth perception, and peripheral vision - These symptoms can impact daily activities like reading, driving, and sports. 
• Post-traumatic vision syndrome (PTVS) - This is a clinical diagnosis for visual symptoms that appear following a brain injury, including a disconnect between central and peripheral vision.

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A Note About Delayed Symptoms: Some individuals may experience vision problems three months or more after the initial injury. 

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The Role that Eye Care Professionals Play in Diagnosing Concussions in Athletes

Clinicians are positioned to play a pivotal role in concussion early detection and management. Visual field tests and extraocular motility (EOM) tests can become your powerful allies in identifying concussion-related visual and neurological dysfunctions.

Athletes may present to your office with concern that their concussion(s) have impacted their vision or neurological function. Alternatively, athletes may present with symptoms but fail to realize that a concussion that occurred during their sport is the root cause of those symptoms.

A comprehensive visual field and other diagnostic tests, such as extraocular motility (EOM), can give you critical data needed to diagnose short- or long-term injuries and collaborate with the patient’s primary care physician on a treatment plan.

Visual field testing should be part of a comprehensive neurological evaluation, including assessments of cognitive function, balance, and other neurological parameters. When assessing athletes for potential neurological damage after they have suffered isolated or repeated concussions, eye doctors should consider a comprehensive approach that includes several key visual fields and related tests, including:

Kinetic Perimetry (Goldmann Perimetry) - This method can help evaluate peripheral vision and identify specific patterns of visual field loss. It can be beneficial when concerns about subtle peripheral defects exist.   

Frequency Doubling Technology (FDT) - This test is sensitive to detecting early visual field changes and can help identify subtle neurological dysfunction.

EOM Testing - This test is critical for evaluating eye movement and coordination, as concussions can disrupt the neural pathways controlling eye muscles, leading to convergence insufficiency, saccadic dysfunction, and nystagmus.

Pupillary Light Reflex - Assessing the pupil's reaction to light is a quick and basic test that can give insight into neurological function. Abnormal pupillary responses can indicate neurological damage.   

Saccadic and Smooth Pursuit Testing - These tests evaluate the eye's ability to quickly move between targets (saccades) and smoothly follow moving objects (smooth pursuit). These eye movements are neurologically complex and are often affected by concussions.   

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The Importance of Baseline Testing in Patient Athletes

Ideally, athletes should undergo baseline visual field and EOM testing before participating in contact sports. This provides a valuable point of comparison in the event of a concussion. Eye care practitioners should capture patient hobbies and career data on patient intake forms. For those patients who regularly participate in athletic competitions, especially contact sports, clinicians should consider conducting routine visual field exams to monitor progression.

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Review this video for more information on visual field billing.

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The Benefit of Virtual Reality Visual Field Testing Over Traditional Tabletop Perimeters in Caring for Concussed Athletes

Traditional perimetry, while effective, can be challenging or uncomfortable for athletes, especially those who have experienced head, back, and neck trauma. Advancements like virtual reality visual field testing offer a promising alternative. VR-based systems provide a more engaging and immersive experience, potentially improving patient compliance and yielding more accurate results. It also provides a more comfortable modality that doesn't require a back or neck strain while leaning into the tabletop testing device. 

For doctors who really want to go above and beyond, taking a portable virtual field to your nearby high school at the beginning of sports seasons allows you to offer baseline fields testing on all athletes. If parents or coaches later suspect an athlete has been concussed, they can return to your office for repeat testing to assess for changes or restrictions.

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An Empathetic Approach to Athlete Patient Care

We must remember that behind every test result is an athlete and a competitor passionate about their sport, to whom you may need to break the news that continued contact sport participation could be detrimental to their long-term vision and overall health. Coordinating care with athletic trainers, coaches, primary care physicians, physical therapists, neurologists, and family members provides the greatest compass of care that keeps the patient at the core of the treatment plan.

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Final Thoughts

By incorporating visual field and EOM tests into your clinical practice and routine testing for active youth and adults, you can empower athletes with the knowledge and support they need to protect their vision and neurological health. This Eye Safety Month, let's commit to raising awareness about the importance of early concussion detection and advocating for comprehensive eye care for athletes of all levels. Together, we can make a significant difference in safeguarding their vision and well-being.