Treva Lind / The Spokesman Review
A technology that measures how the eye’s pupil responds to light shows promise in research as a screening tool for childhood autism — with the aim of making interventions in infancy that could significantly impact a child’s development, Ein said Washington State University researchers.
Children with autism are not diagnosed until the age of 4 on average, missing out on crucial times when they develop speech and language.
“We know that an intervention as early as 18 to 24 months of age has a long-term impact on their outcomes,” said WSU’s Georgina Lynch, a former speech-language pathologist who worked with autistic children. “Intervention during this critical window could mean the difference between a child acquiring verbal language and being left without words.”
Lynch is an assistant professor at Elson S. Floyd College of Medicine and the lead investigator in a study that used what is known as a handheld monocular pupillometer to test one eye at a time to measure how the pupils change when exposed to light. There is still research to be done, but the first study tested 36 children ages 6 to 17 who had previously been diagnosed with autism, along with a control group of 24 typically developing children.
The study, published in Neurological Sciences, found that children with autism had significant differences in the time it took their pupils to contract in response to light. In children with autism, it also took longer for the pupils to return to their original size after the light was removed.
The goal is to develop handheld technology that could be used as part of a screening procedure to provide an objective measure of risk for autism, Lynch said.
“Currently, the tools used are all behavioral. You are subjective. They observe the behavior or rely on a behavior report from the parents. This would allow a pediatrician to have a safe additional marker to make that decision with a full assessment,” Lynch said. “It’s really important to understand that this supports the screening phase. It’s not a diagnostic process, but it supports that screening process to get to that diagnosis sooner.”
“As a clinician, I’ve noticed this condition in children with autism spectrum disorder, where their pupils were very dilated, even in bright light,” Lynch said. “This system is modulated in the brain by cranial nerves that are rooted in the brainstem, and neighboring cranial nerves affect your ability to acquire speech and language.”
It’s getting a little more scientific, she said. “There are what are called primary process systems deep in the brain that are dysfunctional,” including some nerves that affect how the pupils respond to light.
Other nerves in the brainstem function similarly, affecting speech, language development, and hearing.
“If we think about children with autism, since all of these things are disrupted during development, the pupillary light reflex is a good non-invasive measure to see if this part of the brain is functioning efficiently.”
This pupillary light reflex is the research term for how pupils react to light.
Lynch said that the different nerves are very close together.
“It allows us to assess the integrity of how these nerves are functioning. It was logical that we would consider this pupillary light reflex as a screening indicator for a disturbance in the neural development of processes in the brainstem,” she said.
For autistic children, “there are delayed responses on the return to the exit side and accelerated constriction on the other side.”
Lynch, the study’s first author, is developing separately wearable monocular technology for a device that could be used in doctor’s offices. She is preparing to seek Food and Drug Administration approval for the screening device through Appiture Biotechnologies, a company she co-founded.
With funding from the Washington Research Foundation, Lynch has begun additional research at a younger age group, eventually enrolling at least 300 young children ages 2 to 4 at additional clinical sites, including Spokane, Seattle and Pennsylvania, where a large autism center is located.
The Northwest Autism Center, located near WSU’s Spokane lab, is one of the clinical sites for working with young children.
An estimated one in 44 children in the United States will be diagnosed with an autism spectrum disorder by age 8, according to the Centers for Disease Control and Prevention. Many children are misdiagnosed or missed due to the subjective nature of the tests, which are often based on behavioral signs, Lynch said.
Lynch said her desire to improve autism screening stems from her experience of how parents struggle through the cumbersome process of getting their children a formal diagnosis.
Previous studies have found abnormalities in the pupillary light reflex of children with autism. That includes a Lynch-led study that tested children with different technology that measured both eyes at the same time. The use of monocular technology in the more recent study made it easier to use the tests in a clinical setting, and because a device similar to the screening tool Lynch is developing would be commercially available.
Appiture has just prototyped handheld technology to measure the pupil’s response to light, she said, and a next step is to test it in children later this year and next in collaboration with the FDA.
“The hope is to integrate it with some of this Phase 2 research and with at least one group of 50 children,” she said. It would be developed using touchscreen technology, allowing providers to access an instant database of pupillary light reflex responses.