Technology that measures how the eye’s pupil respond to light is showing promise in research as a childhood screening tool for autism – with a goal of toddler-age interventions that could significantly affect a child’s development, a Washington State University researcher said.
Children with autism, on average, aren’t diagnosed until age 4, which misses crucial times when they are developing language and speech.
“We know that when we intervene as early as ages 18 to 24 months, it has a long-term impact on their outcomes,” said Georgina Lynch with WSU, previously a speech-language pathologist who worked with autistic children. “Intervening during that critical window could be the difference between a child acquiring verbal speech and staying nonverbal.”
Lynch is an assistant professor at the Elson S. Floyd College of Medicine and a lead researcher in a study that used what is called a portable monocular pupillometer for testing one eye at a time to measure how the pupils change in the presence of light. There will be ongoing research, 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 children with typical development.
The study published in Neurological Sciences found that children with autism showed significant differences in the time it took for their pupils to constrict in response to light. It also took longer for pupils to return to original size after light was removed among children with autism.
The goal is to develop handheld technology that could be used as part of a screening procedure to offer an objective measurement of risk for autism, Lynch said.
“Currently, the tools that are used are all behavioral in nature. They’re subjective. They’re observing behavior or relying on a parent report of behavior. This would allow a pediatrician to have a confident additional marker to make that decision to do a full evaluation,” Lynch said. “It’s really important to understand that this is supporting the screening stage. It’s not a diagnostic process but it bolsters that screening process to get to that diagnosis earlier.”
“As a clinician, I noticed this state in kids with autism spectrum disorder where their pupils were very dilated even in the presence of bright light,” Lynch said. “That system is modulated in the brain by cranial nerves rooted in the brainstem, and adjacent cranial nerves affect your ability to acquire speech and language.”
It gets a little more scientific, she said. “There are what we call primary process systems deep in the brain that are disrupted,” including some nerves that affect how pupils react to light.
Other nerves in the brainstem function similarly, affecting speech, language development and hearing.
“As we think of kids with autism, as all of those things are disrupted during development, the pupillary light reflex is a good noninvasive measure to look at whether this part of the brain is functioning efficiently.”
This pupillary light reflex is the research term for how pupils react to light.
Lynch said the different nerves are very close together.
“It lets us assess the integrity of how those nerves may be working. It made logical sense that if we looked at that pupillary light reflex as maybe a screening indicator for disruption in neural development of what’s occurring in the brainstem,” she said.
For autistic kids, “it’s delayed responses on the return to baseline side of it and accelerated constriction on the other side of it.”
Lynch, the study’s first author, is separately developing portable monocular technology for a device that could be used in physicians’ offices. She’s preparing to file for Food and Drug Administration premarket approval for the screening device through Appiture Biotechnologies, a company she co-founded.
With funds from the Washington Research Foundation, Lynch has begun additional research among a younger age group, eventually to include at least 300 young children ages 2 to 4 across more clinical sites that include Spokane, Seattle and Pennsylvania, where a major autism center is located.
The Northwest Autism Center, near the WSU Spokane lab, is one of the clinical sites for work with the young children.
An estimated one in 44 children in the U.S. are diagnosed with autism spectrum disorder by age 8, according to the Centers for Disease Control and Prevention. Many kids get misdiagnosed or missed because of the subjective nature of testing, which is often based on behavioral signs, Lynch said.
Lynch said her desire to improve autism screening grew from her experiences watching parents struggle through the cumbersome process of getting a formal diagnosis for their children.
Earlier studies have found abnormalities in pupillary light reflex of children with autism. That includes a study led by Lynch that tested children using different technology that measured both eyes at once. The more recent study’s use of monocular technology made it easier to apply the testing in a clinical setting, and as a similar device to the screening tool Lynch is developing that would be commercially available.
Appiture has just developed a prototype for handheld technology to measure pupil response to light, she said, and a next step is to test that with children later this year and next year while working with the FDA.
“The hope is to integrate it with some of that Phase 2 research and with at least a group of 50 children,” she said. It would be developed with touchscreen technology so that providers can access an immediate database on pupillary light reflex responses.
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