Optometrists have important role in brain injury assessment, rehab

Optometry is the profession of vision. Unlike other professionals in eye care, optometrists are uniquely trained and experienced in the human visual system.

As brain science and neurology have evolved, it is the visual system that provides both diagnostic and therapeutic options for the management of neurologic disorders. This issue features four scientific updates that illustrate optometry’s expanding role in the neurosciences.

Source: Scott A. Edmonds, OD, FAAO

OCT, a commonly used tool for many optometrists, may offer biomarkers for Alzheimer’s disease, according to proceedings of the Retinal Imaging and Neurodegenerative Diseases workshop. The broad geographic access to optometrists with this technology has put us at the forefront for the early detection and intervention of a disease that may affect more than 150 million Americans by 2050.

A new study by Rowe and colleagues found that visual acuity defects are a common problem in the early days of post-stroke management. Early identification of these issues as well as visual field defects, oculomotor problems and visual processing are critical in stroke recovery and management.

In a recent blog from the Neuro-Optometric Rehabilitation Association, neuro-optometrist Dr. Alex Andrich and his occupational therapist wife Patti point out the role of primitive reflexes that can complicate the recovery of patients suffering traumatic brain injury.

Vision impairment has also been found, in another study by Saydah and colleagues, to be linked to other functional limitations and cognitive decline.

The role of the optometrist in stroke and brain injury for early assessment as well as a member of the rehabilitation team is critical.

Scott A. Edmonds, OD, FAAO

Primary Care Optometry News Editorial Board Member

Ocular imaging may facilitate early Alzheimer’s diagnosis

Early identification of the Alzheimer’s disease process would provide the opportunity to intervene when damage to synapses and neuronal tissue is minimal.

Therefore, detection and monitoring techniques with high sensitivity are necessary, said Peter Snyder, PhD, co-chair of the Retinal Imaging and Neurodegenerative Diseases workshop, held in Washington in May.

The American Optometric Association provided a report on the workshop to Primary Care Optometry News. The AOA’s chief public health officer, Michael Duenas, OD, FNAP, participated in the event that hosted 90 researchers from nine countries.

The workshop highlighted different imaging modalities and methods, identified areas of data convergence, and explored gaps and potential areas to further advance application of these technologies for clinical trials and diagnostic uses.

The purpose of the think tank session was to lay the groundwork for large-scale early detection and monitoring of mild cognitive impairment and Alzheimer’s disease, the AOA reported. According to co-chairs, Peter Snyder, PhD, and Heather Snyder, PhD, this is a necessary step in identifying effective treatments for these neurodegenerative diseases, of which early preclinical biomarkers are uniquely amenable to noninvasive retinal/ocular imaging, with the eye serving as the window to the brain.

The next important milestone, according to Peter Snyder, PhD, is “the identification of validated retinal/ocular noninvasive biomarkers that could become essential to algorithms that may contain other markers apart from retinal/ocular biomarkers.” The importance of this effort lies in the data, which predict 152 million people to develop Alzheimer’s disease by 2050, with the world cost expected to reach $2 trillion by 2030 (Patterson).

The take-away message was that amyloid-beta plaque drives tauopathy and inflammation, leading to synaptic damage and neurologic/cell disfunction, the AOA reported. The researchers’ view was that we need to identify the disease process early to intervene during the prodromal phase when damage to synapses and neuronal tissue is minimal. We, therefore, “need detection and monitoring techniques with high sensitivity,” Peter Snyder, PhD, said.

A broad range of prominent world-class researchers shared prepublication concepts at the workshop, the results of which will be compiled into a soon-to-be-released white paper that will lead, it is hoped, to larger and more effective clinical trials.

Just a few of the many highlights of the 2-day meeting included: Astronaut Larry DeLucas, OD, PhD, provided insights to amyloid-beta and protein tau structures. Brett E. Bouma, PhD, discussed advanced use of 3D macular scans and blood flow measurement. Gregory P. Van Stavern, MD, reviewed retinal nerve fiber layer algorithms with cognitive testing overlay. Maya Koronyo-Hamaoui, PhD, discussed enlarged foveal avascular zones and retinal sweet spots. Melanie Campbell, MSc, PhD, covered cross-polarized light for predicting earlier stages of disease. Peter van Wijngaarden, PhD, FRANZCO, discussed hyperspectral retinal imaging. Robert Rissman PhD, presented a real-world trial of retinal imaging. Marius Tresor Chiasseu, PhD, covered building a consensus on methodology. Silvia Di Angelantonio, PhD, reviewed microglia activation at the preclinical phase and imaging of neuroinflammation in the retina. SriniVas R. Sadda, MD, presented fluorescence lifetime imaging ophthalmoscopy in neurodegenerative diseases. Chiara La Morgia, MD, PhD, discussed sleep disturbances and melanopsin-retinal ganglion cell degeneration.

The AOA said that one day Alzheimer’s disease could be another responsibility for optometry within team-based medical management, which is why it is imperative for doctors of optometry to stay current on the latest continuing education and become involved in clinical research projects. “Pairing technology and understanding of early cognitive decline is going to be essential in raising our patients’ health outcomes and preventing or slowing neurodegenerative disease,” Duenas said.

Doctors of optometry who routinely use OCT and OCT angiography are already on the leading edge of ocular and systemic disease detection, and this research shows an opportunity to make a difference, the AOA said. Altogether, 276 systemic diseases have ocular findings that can be detected during a comprehensive eye examination that, combined with optometry’s geographic accessibility, position doctors of optometry to substantially contribute to Americans’ primary medical care.

Identifying visual effects of stroke essential to early intervention

More than half of all stroke survivors have problems with visual acuity.

Vision screening and full visual assessment detected these issues within 5 days of stroke, according to a study by Rowe and colleagues published in PLOS ONE.

Issues with visual acuity are an underreported consequence of stroke, so the authors sought to create an annual incidence and point prevalence evaluation on visual acuity in an adult stroke population and also explore early timing of visual assessment after stroke.

In this prospective, multicenter epidemiology study, researchers reviewed data on acute stroke unit patients who were assessed for visual acuity, visual fields, ocular alignment, ocular motility, visual inattention and visual perception. A total of 1,033 stroke survivors completed visual assessment.

Researchers found that these patients underwent visual screening at a median of 3 days and full visual assessment at a median of 4 days after their stroke. The incidence of new visual acuity issues after stroke was 48% for all admissions and 60% for all survivors.

Approximately 75% of patients had visual acuity (point prevalence) effects, 56% had impaired central vision, 40% presented with eye movement abnormalities, 28% with visual field loss, 27% with visual inattention and 5% with visual perceptual disorders.

Researchers concluded that early vision screening is possible within the first 72 hours following stroke. Not only are there possible benefits for patients’ lives but also for their stroke team and care givers by enabling early intervention.

Brad Sutton, OD, FAAO, a clinical professor at Indiana University School of Optometry and service chief at Indianapolis Eye Care Center, commented on these study results:

“As eye care providers, we know all too well the devastating effects that a neurological stroke can have on the visual system. This interesting study, which was performed in three stroke centers in England, sheds light on the severity of this problem.”

Sutton continued: “Most of the patients included in the study underwent visual evaluations within several days of having suffered an acute ischemic or hemorrhagic stroke. Many were actually assessed within the first 72 hours. Issues with the visual system were roughly categorized as affecting central vision, ocular motility, the visual field or visual perception. Overall, 60% of assessed stroke survivors (some patients were too impaired to assess) exhibited one or more new onset visual deficits. Interestingly, patients with visual system abnormalities tended to have suffered much more severe strokes, and their average discharge time from the hospital was 36 days longer than stroke survivors who did not have visual system involvement.”

He concluded: “For interventional and rehabilitative purposes, it is critical to screen for deficits as early as possible, with early identification perhaps leading to early attempts at remediation. This work shows that many stroke sufferers will suffer with visual system abnormalities and, furthermore, that they can often be effectively evaluated very soon after the event. Rapid identification of those in need has the potential to lead to improved long-term outcomes with reduced disability.”

Brain injury can relaunch long-dormant ‘system codes’

PCON bloggers Patti Andrich, MA, OTR/L, COVT, CINPP, and Alex Andrich, OD, FCOVD, said we all inherited several codes when we were developing in our mothers’ wombs – codes for hair color and eye color as well as system codes to run our neurological sensory and motor operations. These primitive codes allowed for the emergence of early patterns of movements, which, in turn, assisted in us being born and learning to sit and stand and eventually perform everyday complex movements.

“The system codes are called primitive reflexes,” they said. “Initially, they are necessary for surviving the birth process and after birth they serve as the basis for ongoing development. Some of these primitive reflexes are well known to anyone who has spent time with an infant: The rooting reflex helps newborns nurse, while the palmar reflex gives a baby that tight grip. The Moro reflex is important for the first breath of life and eventually transforms into the adult startle reflex.”

They continued: “The tonic labyrinthine reflex is important for building core muscle tone and proprioception. This reflex also helps a baby learn about gravity and prepare for rolling over, crawling and walking. The asymmetrical tonic neck reflex ensures that when a young infant turns his head to the right, the right arm and leg extend, and the left arm and leg bend. This movement pattern helps the baby begin to distinguish left and right and leads to early eye-hand coordination.”

Infants use these reflexes as a means to develop sensory and motor skills needed to explore the world around them, Andrich and Andrich said. Primitive reflexes are vital to development, but they are not meant to linger.

“After they have fulfilled their purpose, their activity is suppressed,” the bloggers said. “This occurs sometime around a child’s first birthday. If the primitive reflexes stick around into later years of childhood or into adulthood, they can become quite detrimental. That’s why primitive reflexes ‘hibernate’ once they have served their developmental purpose. Within the first few months or years after birth, they are gradually suppressed by higher-level brain functions and then become ‘integrated’ as the nervous system matures.”

When the brain is injured, such as by a blow to the head or a stroke, higher level cortical functioning shuts down, and primitive survival reflexes that had been stored in the brain can re-emerge, they said.

“As you might imagine, restarting these old system codes can wreak havoc in a person’s life,” they said. “People with brain injuries can lose the ability to walk, talk and think clearly. They often have visual complications in addition to sensory and motor disruptions. In essence, they have to re-learn many skills they had learned early in life.”

Andrich and Andrich offered an example of a man in his early 30s who recently suffered a head injury at work in a factory. As a result, his eye movements became disorganized and he lost the ability to accurately fixate on objects. He also began to suffer from significant vestibular problems and reported “not feeling right in his own skin.” A primitive reflex evaluation revealed that he had what neurologists call the Babinski sign, a re-emergence of a primitive tactile reflex that causes the toes to flare when the sole of the foot is touched.

“Imagine trying to stand when your brain is constantly getting a signal to lift your toes off the floor,” they said. “The young man tried to use his eyes to help his body feel balanced, but he had limited success because his feet created an unstable base of support. He stated he felt the worst when standing. It was clear that in order to improve his visual skills, we would have to start with his feet.”

This patient’s therapy began with reflex integration exercises aimed at getting his toes to grip the floor, to create stability when standing, so that his eyes could re-learn how to move accurately and process visual information.

“It was in treating the neurological basis with an understanding of the role that primitive reflexes play in developing visual skills that we were able to improve his balance, reduce his anxiety and nausea, help him to be comfortable in his own skin again and ultimately improve his visual functions,” they said.

“This is just one of the ways that we use reflex integration activities in our practice to speed up recovery after a brain injury,” said Andrich and Andrich, who practice together. “You can think about the aftermath of a significant brain injury like a house that has been destroyed by a tornado. To rebuild the house, you have to start with the foundation (re-integrating the primitive reflexes) before you can even think about replacing the roof and siding (recovering fine and superfine motor control functions like fixation, convergence and eye tracking).”

Primary care optometrists who see patients after concussion should know that feeling nauseous or uneasy can be related to visual-vestibular problems, the team said.

“We would encourage you to strongly consider referring anyone with these symptoms or balance problems to a neuro-optometrist who can treat the neurological basis for the problems,” they concluded.

Vision impairment linked to functional limitations from cognitive decline

Analysis of data from an annual state-based survey found that adults with vision impairment were 3.5 times more likely to report functional limitations related to subjective cognitive decline, according to a report published in Morbidity and Mortality Weekly Report.

“Vision impairment is associated with social isolation, disability and decreased quality of life,” study author Sharon Saydah, PhD, of the CDC, told PCON in an interview. “Recent CDC research finds a strong association between vision impairment and self-reported cognitive decline. Cognitive decline can result in functional limitations, especially those related to usual daily activities.”

Researchers collected data from 2015 to 2017 using the Behavioral Risk Factor Surveillance System, a telephone survey of non-institutionalized adults. Response rates among states, the District of Columbia and Puerto Rico were a median of 45.7%, with 208,601 adults 45 years and older completing the optional cognitive decline model.

Respondents were classified as having subjective cognitive decline (SCD) if they responded affirmatively to a question regarding increasing confusion and memory loss in the past 12 months. Functional limitations were determined if the respondent felt that confusion and memory loss affected their ability to complete household tasks and activities outside the home. Vision impairment was defined as blindness or serious difficulty seeing, even with glasses.

Multivariate logistic regression models were used to examine the relationship between SCD-related functional limitations and vision impairment, adjusting for covariates including age, sex, education level, race/ethnicity, smoking status and health insurance status.

The study found that 18% of adults 45 years old and older who reported vision impairment also reported SCD-related limitations vs. 4% of those without vision impairment. Vision impairment among respondents was 6.2%, and the prevalence of SCD with functional limitations was 5.5%. The prevalence of vision impairment and SCD-related functional limitations was higher among adults with less than a high school diploma (4.1%) who were current smokers (3.6%) and who did not have health insurance (3%) than for college graduates (04%), those who had never smoked (0.9%) and those who had health insurance (1.4%).

“Interventions aimed at addressing vision impairment through corrective treatment or prevention may reduce functional limitations associated with cognitive decline in the population,” Saydah told PCON. – by Julia Lowndes and Scott Buzby

References:

Patterson C. World Alzheimer Report 2018. www.alz.co.uk/research/WorldAlzheimerReport2018.pdf. Accessed June 6, 2019.

Rowe FJ, et al. PLOS ONE. 2019; doi:10.1371/journal.pone.0213035.

Saydah S, et al. Morb Mortal Wkly Rep. 2019; doi.org/10.15585/mmwr.mm6820a2.

For more information:

Patti Andrich MA, OTR/L, COVT, CINPP, is an occupational and vision therapist and board director of NORA. Alex Andrich, OD, FCOVD, is on staff in the physical medicine and rehabilitation departments at University Hospitals Parma Medical Center and the MetroHealth Rehabilitation Institute of Ohio and serves as president of the International Sports Vision Association. They are in practice together as The Vision Development Team in North Royalton, Ohio (sensoryfocus.com).

Scott A. Edmonds, OD, FAAO, is the chief medical officer of March Vision Care, the co-director of the Low Vision/Contact Lens Service at Wills Eye Institute in Philadelphia and a member of the PCON Editorial Board. He can be reached at: scott@edmondsgroup.com.

Disclosures: Andrich and Andrich report no relevant disclosures. Duenas is the AOA’s chief public health officer. Edmonds is a consultant for March Vision. Rowe and colleagues report no relevant financial disclosures. Saydah and colleagues report no relevant financial disclosures. Sutton reports no relevant disclosures.