Eye test may provide way to diagnose autism in children

One of the most frustrating aspects of autism for doctors and parents is the lack of a definitive tool for diagnosing the developmental disorder in children.

Now, researchers at the University of Missouri at Columbia report some early results that point to a potential testing method involving the pupil of the eye.

Using changes in light, the researchers compared the pupil response times of children with autism to a control group of other children.

The pupils of young people who had previously been diagnosed with autism were slower to constrict when presented with a flash of light.

The test was 92.5 percent accurate in predicting which children had autism, researchers said.

Researchers had hypothesized that pupil response is connected to other areas in the brain that are affected by autism. Their hypothesis was based on animal research that connected pupil reflexes to neurological pathways.

"We found it's a possibility that those parts of the brain may be affected by light," said Gang Yao, associate professor of biological engineering. "Because autism is so complicated and can affect many different areas of the brain, we thought maybe there is something wrong in the pupillary light reflex in children (with autism). You can clearly see the difference."

Yao cautioned that the study results are very preliminary and include an extremely small sample size.

The study included 24 people ages 6 to 20 who had been diagnosed with autism and a control group of 44 people.

Another drawback of the study is that the group with autism all had similar diagnoses. Autism is considered a spectrum disorder that can vary widely in how it affects people. It's not known yet if the pupil reacts the same in people with all types of autism.

Yao worked with Xiaofei Fan, a postdoctoral fellow; child health professor Judith Miles; and Nicole Takahashi, a senior research specialist at MU's Thompson Center for Autism and Neurological Disorders.

Their research was published in the Journal of Autism and Developmental Disorders.

The group received a grant recently from the National Institutes of Health to expand the study over the next couple of years to include more children and a more diverse range of autism diagnoses.

Distributed by McClatchy-Tribune Information Services.