By Dr. Dorothy Hitchmoth
In the recent movie Concussion, actor Will Smith, playing the now infamous doctor Bennet Omalu, says, “repetitive head trauma chokes the brain”. I know this is true. My 20 years as a VA eye doctor is a privilege that bears the reality of the effects of repeat brain trauma as well as the perseverance embedded in the souls of our nation’s finest men and women. My perspective on treating these patients is hardly mired given my proverbial view to the brain.
Science has proven that the eye and brain are inseparable and can really be thought of as a common system bound by shared anatomy, function and blood supply. In fact, it is a well-conceived notion that the eye is the canary of the mind. “The retina is actually a piece of the brain that has grown into the eye and processes neural signals when it detects light” at about “the same rate as an Ethernet connection”, according to NIH researchers. 1
The retina is responsible for capturing visual information and transmitting it to the brain in a variety of ways. The nerve responsible for vision (optic nerve) is easily seen and measured during an eye exam. This nerve traverses the entire brain and research has already revealed several biomarkers of brain disease that can be visualized through the eye.
Measuring the optic nerve and exam of the lens in the eye has revealed clues about Alzheimer’s disease, multiple sclerosis, neuromyelitis optica, glaucoma and Parkinson’s disease. 2-11 Similarly, the eye reveals clues about patients affected by chronic brain injury such as concussion and multiple concussion (mTBI). Optic nerve integrity can be measured by ocular coherence tomography (OCT), visual evoked potential (VEP), pattern electroretinagram, and pupillography. These tests are performed by eye doctors and help detect damage in the eye and brain. 12-14 Moreover, light absorbing pigments in the retina, also known as macular pigments, can be measured through a technique called macular pigment optical density (MPOD). This test is a simple, two-minute test that many eye doctors perform in office that provides insight about nutrient intake of lutein and zeaxanthin. Lutein and zeaxanthin are plant pigments seen in some of the healthiest fruits and vegetables that protect the visual center of the retina known as the macula. Low measures of MPOD have been associated with disease states such as macular degeneration, diabetes, glaucoma, poor visual performance and lower cognitive function. Normal and optimized MPOD measures are associated with significantly improved visual function in study groups of high performance athletes and the elderly, two groups at risk for brain injury. Study groups who took supplemental lutein and zeaxanthin had significantly improved measures of acuity, contrast acuity, glare disability, and other measures of visual function. These measures are very important in both high performance athletics as well as improved driving vision in the elderly for example.15-26
Given these insights, it should not be surprising that nutrients that support eye health are also implicated in brain homeostasis.
Omega 3 polyunsaturated fatty acid (PUFA) (fish oil: DHA/EPA), alpha lipoic acid, Vitamins A, D, E, B6, B12, Selenium, Manganese, CoQ10, anthocyanin, zeaxanthin, and lutein are all nutrients that support healthy eye and brain function. This list is not exhaustive and other dietary and supplemental source nutrients to include certain antioxidants such as polyphenols and curcumin as well as other medium chain fatty acids, such as those found in coconut oil, are being studied for potential benefit in neurodegenerative conditions to include brain injury. 26-34 It is also important to know that the eye and brain has the highest concentration of lutein, zeaxanthin and DHA/EPA (omega 3 -fats) in the body.34-37
The nutrients noted here are important for eye-brain protection and function despite the fact that many factors and complex mechanisms have been identified in diseases and/or trauma to these important organs-many of which have yet to be fully understood. There is a need for more research in this area, however, there is general scientific consensus that inflammation, oxidative stress and interruption of the eye-brain-blood barrier are implicated in the chronic stages of eye and brain disease such glaucoma, macular degeneration, diabetic retinopathy as well as early and late phase effects of concussion.38-40 The nutrients implicated herein are regularly prescribed by eye doctors because many of these nutrients are needed for improved visual performance and in the management of age-related macular degeneration and dry eye disease. Similarly, certain lifestyle implications such as dietary glycemic load (sugar), body weight (obesity), smoking and other epigenetic factors have all been associated with poorer outcomes in patients with certain eye disease and those who experience brain trauma.
Therefore, it seems it is not a scientific leap to beg the question: Can nutraceutical support of visual function help protect the brain from concussion? Future research will better answer this question, however, it seems prudent to advise patients who are at risk for concussion about the importance of good nutrition and smoking cessation. This is especially important advice for young athletes, who have developing brains and who are high risk for concussion. Preparing the visual system and brain with a healthy diet or dietary sourced nutrients will prevent other poor outcomes associated with a “junk food and beer” lifestyle. Seems we have nothing to lose. Similarly, measuring MPOD in the eye doctor’s office may provide insight about the dietary habits and visual abilities of these young athletes. Athletes with low MPOD can be advised to change their diets and consider supplemental forms of important vision nutrients. I see little risk in preparing athletes for a lifetime of good health habits with the presumption that your good advice may help thwart some of the effect of brain injury as well as help in recovery. The concept of “pre-treatment” is an important emerging science that bears attention. Concussion rates in the NFL were reported to have increased 58% last year and as many as one in five high school athletes will suffer a concussion. 41-42 These facts warrant better prevention programs like those at University of Cincinnati. Dr. Joe Clark, professor of neurology and associate director of the UC Sports Neuroscience Initiative (SNI), is part of a holistic concussion prevention program at UC that has helped athletes strengthen their peripheral vision, reaction time and eye-hand coordination. His training program has resulted in a significant drop in season play concussion.
In my view, eye doctors (optometrists and ophthalmologists) are also well-positioned to impact concussion outcomes especially in brain injury associated with mild and repeat concussion because these are often underdiagnosed. Optometrists should be part of the care team in this fight because they interface with two-thirds of the population. More importantly, they are experts in the measurement of eye-brain dysfunction, they provide neuro-ocular rehabilitation to patients with brain injury, and they are seasoned purveyors of risk who regularly give health and medical advice to patients. Perhaps one day a visit to the eye doctor will be a routine and required part of pre-concussion prevention programs.
Technological advancements in the measurement of eye and brain function, head and neck protection, and brain science, will carve a future path that helps us protect our brains even better, however, I believe we can impact patient lives now. A little food-for thought.
Dr. Hitchmoth is Chief of Optometry and Director of Residency at the VAMC White River Junction. She is a private practice owner and CEO of New England Telehealth. Dr. Hitchmoth is a nationally-recognized award-winning professor, lecturer, educator and thought leader. Her publication and research interest centers on retinal biomarkers of systemic disease. @eyedocdorothy
Disclosures: Dr. Hitchmoth is a paid consultant for Zeavision, LLC and Shire Ophthalmics Inc
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