The fast, cheap eye test that could potentially diagnose autism

A new study has raised hopes for the development of a fast, cheap diagnostic test for autism in children.  The latest research focused on the penlight reflex test, a basic procedure, which involves the doctor shining a light in the patient's eye. The light causes the pupil to dilate as it adapts, then constrict when the light is taken away. In a small study of 24 children aged between 10 and 17, half of whom had been diagnosed with high-functioning autism, revealed that, in 70 per cent of cases, the pupils of children with autism took significantly longer to constrict. Study lead Dr Georgina Lynch believes a pupil abnormality could explain why many children with autism have trouble making eye contact.

Dr Lynch explained: "Deficient functioning of these two cranial nerves makes it challenging for a child to maintain eye gaze. This is necessary for developing joint attention and for paying attention to dynamic features of a person's face.

"These fundamental physical behaviours are needed to develop language and socialisation."

While larger studies will be necessary to validate the findings and clinical trials begin next year, the research team at Washington State University hope that their discovery could pave the way to faster diagnosis of autism in children, which would speed up early intervention. “Our results suggest that an inexpensive, noninvasive pupil penlight reflex test could be a physiological measurement of autism,” added Dr Lynch.