A simple eye test at the opticians could diagnose children with autism, a study suggests.
American researchers found that the eyes of young people with the condition react more slowly when exposed to bright light.
Their pupils took longer to constrict and return to their original size.
Researchers hope the finding paves the way for a “quick and easy” way to diagnose autism — which is often a lengthy and stressful experience for families.
They believe the delayed reaction time is a sign that the nerves in the brain are not working at full capacity.
A faster diagnosis can lead to earlier interventions that can make all the difference in whether or not a child with autism can speak in the future.
Autism and related conditions such as Asperger’s affect about one in 100 British children and one in 44 American young people.
The condition is notoriously difficult to diagnose because there is no medical test, meaning doctors must rely on the child’s developmental history and behavior.
As such, children in the US are not normally officially diagnosed until age four, while in the UK the average age is six.
A simple eye test could unlock a quick way to diagnose autism in children. US experts found that children with the condition showed a delayed response in the way their pupils react to direct light, similar to that of an optician.
Lead study Georgina Lynch, an assistant professor at Washington State University, said: “We know that when we intervene as early as 18 to 24 months of age, it has a long-term effect on their results.
Intervening during that critical window can be the difference between a child acquiring verbal speech and remaining nonverbal.
“But after 20 years of trying, we still haven’t changed the average age of diagnosis here in the US, which is four years.”
What are the signs of autism?
Signs of autism in young children include:
- Not responding to their name
- Avoid eye contact
- Don’t smile when you smile at them
- Getting very upset if they don’t like a particular taste, smell, or sound
- Repetitive motions, such as clapping their hands, waving their fingers, or rocking their bodies
- Not talking as much as other children
- Repeating the same sentences
Signs of autism in older children include::
- Not seeming to understand what others are thinking or feeling
- Find it hard to say how they feel
- Keeping a strict daily routine and getting very upset when it changes
- Have a very strong interest in certain topics or activities
- Get very upset when you ask them to do something
- Do you find it difficult to make friends or do you prefer to be alone
- Taking things very literally – for example, they may not understand phrases like ‘break a leg’
Common symptoms of autism in adults include:
- Finding it hard to understand what others are thinking or feeling
- Becoming very anxious about social situations
- Do you find it difficult to make friends or do you prefer to be alone
- Appearing rude, rude or uninterested in others without wanting it
- Find it hard to say how you feel
- Taking things very literally – for example, you may not understand sarcasm or phrases like ‘break a leg’
- Having the same routine every day and getting very anxious when it changes
The research team tested the eyes of 60 children between the ages of six and 17.
Of these children, 36 had been previously diagnosed with autism, while the rest served as controls.
Scientists used a handheld device called a pupillometer, which emits a bright light and is available from most opticians.
They test children’s eyes one at a time and measure the pupillary reflex, a scientific term for how quickly the eye’s pupil changes shape in response to bright light.
When they analyzed their results, they found that children with autism had a significantly delayed reflex reaction time compared to the controls, with the eyes taking longer to respond and also longer to return to normal.
Professor Lynch, an expert on speech and hearing, believes the delayed response time is a sign that the cranial nerves in the brain — which control speech in language — are defective.
She said the eyes are “modulated in the brain by cranial nerves rooted in the brainstem, and adjacent cranial nerves affect your ability to acquire speech and language.”
“The pupillary reflex tests the integrity of that system, so it seemed logical to try this very simple, non-invasive measure to determine if there are differences between typical development and autism,” she added.
The findings are published in the journal Neurological Sciences.
Professor Lynch said the team is working on a new study in a group of 300 two- to four-year-olds.
This study will enable them to establish the exact benchmarks for the delayed response that could identify a child with autism.
Autism refers to a wide variety of conditions characterized by problems with social skills, repetitive behavior, speech, and nonverbal communication.
Families are often forced to attend multiple hospital appointments, and children must undergo various psychological tests to receive a diagnosis.
While medications can be given to control symptoms such as aggression or hyperactivity, there is no cure.
Affected children may have difficulty making eye contact, understanding how others are feeling, or taking a keen interest in certain topics.
Autistic youngsters may also take longer to understand information or to repeat things.
