Your Eyes Could Be Hiding a Biomarker for ADHD and ASD, According to Aussie Research

Your Eyes Could Be Hiding a Biomarker for ADHD and ASD, According to Aussie Research
Image: Zachariah kelly/Gizmodo Australia

New research from Flinders University indicates that your eyes could reveal insights into neurological disorders like ASD and ADHD.

According to the research, recordings from the retina could identify signals for ADHD (Attention Deficit Hyperactivity Disorder) and ASD (Autism Spectrum Disorder).

This research could provide a biomarker for both conditions. That is, an identifiable biological measure for a biological state. Biomarkers have long been difficult to define for ADHD and ASD.

As someone who has been diagnosed with ASD as an adult and was incorrectly diagnosed with ADHD growing up (that sucked), this sounds both terrific and a bit problematic.

A biomarker for a neurological disorder sounds like a breakthrough that could, potentially, guide treatments and medications along the right way. That being said, depending on the depth of further research, the potential biomarker would need to be highly accurate, were it not to exclude people with neurological disorders that didn’t pass the biomarker test.

An “electroretinogram” (ERG) was used to diagnose how the retina responds to light stimuli, by measuring its electrical activity. In the research, children with ADHD were found to have more ERG energy, whereas children with ASD were found to have less ERG.

“ASD and ADHD are the most common neurodevelopmental disorders diagnosed in childhood. But as they often share similar traits, making diagnoses for both conditions can be lengthy and complicated,” said Doctor Paul Constable, a research optometrist at Flinders University.

“Our research aims to improve this. By exploring how signals in the retina react to light stimuli, we hope to develop more accurate and earlier diagnoses for different neurodevelopmental conditions.

“This study delivers preliminary evidence for neurophysiological changes that not only differentiate both ADHD and ASD from typically developing children, but also evidence that they can be distinguished from each other based on ERG characteristics.”

Briefly, let’s just explain what both of these disorders are. ADHD is often characterised with hyperactivity, struggling to pay attention and difficulty controlling impulsive behaviours.

ASD, on the other hand, is an umbrella term used to describe when someone has difficulty behaving, communicating, interacting and learning in ways that are considered ‘different’ to most other people.

They’re pretty different, but often they can have similar characteristics. As per the World Health Organization, one in 100 children has ASD, whereas between five and eight per cent of children are diagnosed with ADHD.

“Ultimately, we’re looking at how the eyes can help us understand the brain,” added Doctor Fernando Marmolejo-Ramos, a co-researcher and an expert in human and artificial cognition from the University of South Australia.

“While further research is needed to establish abnormalities in retinal signals that are specific to these and other neurodevelopmental disorders, what we’ve observed so far shows that we are on the precipice of something amazing.”

This was an early study with a very limited amount of control individuals. More studies will, of course, need to be done to see if a biomarker can be found for ADHD and ASD in the eyes.

We’ve reached out to the ADHD Foundation and Autism Spectrum Australia for comment on the research.

You can read the media release from Flinders University here. You can read the research in Frontiers in Neuroscience.