As the old adage goes, an ounce of prevention is worth a pound of cure. Given the state of healthcare expenditures in the U.S. today, this valued insight has tremendous relevance. Of the nation’s total GDP, roughly 18 percent goes toward healthcare expenses. And despite these investments, the U.S. boasts far less superior patient outcomes than many other countries. Because of this, healthcare scientists are focusing more and more on preventative efforts to detect illnesses earlier. They also appreciate screening measures that are both inexpensive and easy to use. This has led to some pretty interesting considerations recently, especially with major advances in consumer technologies.
Most everyone is aware of the boom in health and fitness apps as of late. (Read more about that boom in this Bold story!) But this is likely just the tip of the iceberg when it comes to consumer engagement in self-care. Recently, researchers at the University of California in San Diego explored how an eye-selfie test might reveal early neurological illness. Using a neurological screening app that measures pupillary size changes, they observed some intriguing findings. For several brain-related conditions, their eye-selfie test showed changes that seemed to correlate well with more involved and costly testing. If these findings can be validated for specific illnesses, then their neurological screening app could be a game-changer.
“While there is still a lot of work to be done, I am excited about the potential for using this [eye-selfie test] technology to bring neurological screening out of clinical lab settings and into homes.” – Colin Barry, Electrical and Computer Engineering Ph.D. student, UC San Diego
A Window to the Soul and the Brain
For many years, clinicians and researchers have recognized that pupillary changes often correlate with some neurological conditions. In essence, our pupils constrict and dilate as a result of specific nerve inputs and neurochemicals. Therefore, if an illness affects these nerve impulses or chemical substances, pupillary movements may change. This may not only involve the speed with which constriction and dilation may occur but also the degree. This has led to using specific tests to assess these pupillary changes, which involves the use of in-office medical equipment. In recent years, it has been recognized that pupillometry can often provide early detection of some neurological diseases.
Interestingly, with advances in smartphone technologies, an in-office pupillometry machine may no longer be required. The eye-selfie test being proposed by UCSD researchers requires only the use of an everyday smartphone camera. Relying on the near-infrared capabilities of most built-in smartphone cameras, pupillary size changes can be tracked. In fact, the precision with which the eye-selfie test measures these changes are nearly as good as the in-office machines. Driven by a neurological screening app, changes in the speed and size of pupillary constriction and dilation can be determined. And if abnormal, it could indicate a number of conditions that range from dementia to neuropathy.
“A scalable smartphone assessment tool that can be used for large-scale community screenings could facilitate the development of pupil response tests as minimally-invasive and inexpensive tests to aid in the detection and understanding of diseases like Alzheimer’s disease. This could have a huge public health impact.” – Eric Granholm, Professor of Psychiatry, UC San Diego School of Medicine and Director of the MHTech Center
Neurological Conditions for Pupillary Screening
It might seem odd that pupillary changes can suggest early disease. But the mechanisms that cause pupillary constriction and dilation share common pathways with other brain functions. Specifically, our autonomic nervous system regulates these changes. Therefore, diseases that alter autonomic nerve impulses can cause delays in the velocity or size of pupillary movements. In fact, pupillometry has been shown to provide early detection of diabetic neuropathy because of this. Using the neurological screening app and the eye-selfie test, early neuropathy disease could potentially be identified. In turn, this might offer earlier treatment to delay progression or even detect the presence of diabetes.
The neurological screening app may be used to detect the presence of other illnesses as well. The same eye-selfie test could show speed and size changes in pupillary movements reflective of some dementias. Specifically, reductions in cholinergic chemical activity in Alzheimer’s dementia causes such changes in pupillary activity. Even those with early brain tissue changes without clinical disease show slowed and reduced pupillary dilation and constriction. Pupillometry has also been used in screening for Parkinson’s disease and to measure changes in age-related attention spans. Understandably, the neurological screening app and the eye-selfie test could have broad applications.
“For us, one of the most important factors in technology development is to ensure that these solutions are ultimately usable for anyone. This includes individuals like older adults who might not be accustomed to using smartphones.” – Colin Barry
Next Steps for the Neurological Screening App
As you might imagine, one of the issues in using a neurological screening app on a consumer device involves usability. An eye-selfie test sounds simple enough for most, but many older adults lack technology skills in this area. These are notably the same group of individuals who may be higher risk for many neurological conditions. With that in mind, the researchers at UCSD tested their eye-selfie test among hundreds of older individuals. Using voice commands, image instructions, and inexpensive plastic scopes, usability was found to be quite good. Through a process of experimentation and feedback, they were able to refine their neurological screening app for the masses.
At the current time, there is not enough research to clearly define where an eye-selfie test might be useful. Indeed, it is as effective as pupillometry in the early detection of several illnesses. Likewise, the neurological screening app is user-friendly enough for widespread use. But more vigorous testing is needed in larger populations to determine how such a screening test may be most effective. Several researchers are in the process of doing just that in an effort to better guide screening practices. But existing research looks incredibly promising. In addition to data from our wearable devices, we might soon be sending eye-selfie-test results to our providers as well.