The sparkle in an eye may be a clue to neurological conditions

Eyes may be the window to the soul but Adelaide researchers believe they can also give clues to ADHD, autism and other conditions.

The eyes have it – the clue to early diagnosis of ADHD or autism, Adelaide researchers say.

The work is “on the precipice of something amazing” as researchers believe electrical energy in the retina is the key to early detection of different neurological conditions.

In the first study of its kind, Flinders University and University of South Australia researchers found recordings from the retina could identify distinct signals for both Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD), revealing a potential biomarker for each condition.

Using the electroretinogram (ERG) – a test that measures the electrical activity of the retina in response to a light stimulus – researchers found children with ADHD showed higher overall ERG energy, while children with ASD showed less ERG energy.

The work was done with 55 people with ASD with an average age of 14, 15 people with ADHD with an average age of 15, and a control group of 156 people with an average age of 13.

Research optometrist at Flinders University, Dr Paul Constable, said the preliminary findings indicate promising results for improved diagnoses in the future.

“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,” he said.

“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.”

World Health Organisation data shows one in 100 children has ASD, and 5-8 per cent of children are diagnosed with ADHD.

Tara Adamson with her daughter Tori, 8. Tori was diagnosed with ADHD recently. Her mother Tara says the research is great news because the earlier parents can get diagnosis, the better. Picture: Matt Turner

Co-researcher and expert in human and artificial cognition at the University of South Australia, Dr Fernando Marmolejo-Ramos, said the research has potential to be applied to other neurological conditions.

“Ultimately, we’re looking at how the eyes can help us understand the brain,” Dr Marmolejo-Ramos said.

“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.

“It is truly a case of watching this space; as it happens, the eyes could reveal all.”

Modbury North mother Tara Adamson, whose daughter Tori, 8, was diagnosed with ADHD about 12 months ago, welcomed any move which would help early diagnosis.

“Especially with the learning difficulties and friendship difficulties that ADHD can present,” she said.

“If you knew in advance, then you can be on it earlier. And even better if it’s a non-invasive test.”

The research was conducted in partnership with McGill University, University College London and the Great Ormond Street Hospital for Children.