Test identifies autism with eye analysis in 15 minutes; understand the caveats of the technique used in the US

The test can be performed on babies aged 14 to 30 months in the United States — Photo: reproduction Fantástico

The method, approved in the United States in August 2023, could revolutionize early autism diagnosis. In it, children's eyes are monitored while they watch videos, and results can be available in just 15 minutes . But Brazilian doctors warn of the risks of using a single biomarker in such a complex diagnosis.

The study is led by Brazilian Ami Klin, director of the main autism treatment center in the US, located in Atlanta.

The test was approved by the US regulatory agency in August 2023 and, for now, is administered to children between 1 year and 4 months and 2 and a half years. There is no forecast for the technology to be available in Brazil yet—its use is subject to approval by national regulatory agencies.

Autism is diagnosed clinically and can be diagnosed as early as 18 months. After three years of age, it has greater validity, according to child and adolescent psychiatrist and professor of psychiatry at USP Guilherme Polanczyk.

It involves direct examination, through a direct assessment of the physician with the child, standardized tests, the child's developmental history reported by the parents and often by other informants as well.

Polanczyk explained to g1 that the medical community does not expect a single biomarker for diagnosing autism.

"Lack of eye contact is a very common marker in children with autism. Children often look into each other's eyes in the first year, but after a certain point, this eye contact becomes less and less frequent. Later, this becomes a target for treatment, and people can better develop this skill," says the doctor.

But as autism is very heterogeneous, there are people who didn't have eye contact from an early age, others who had it and then lost it, and others who always maintained it.

Polanczyk further explains that the fact that the new diagnostic method approved in the US was evaluated in a specific sample and in a specific context is the beginning of a process that will need to be validated in other contexts, with other populations.

"It will be necessary to understand, for example, how this marker works in populations with autism and ADHD, autism and sensory difficulties, or just sensory difficulties. Ultimately, there's a biomarker validation process that requires multiple studies. We don't expect a single marker to be able to diagnose something so complex and heterogeneous," he states.

The doctor notes that not 100% of people with autism have impaired eye contact, for example. Often, other issues cause someone to lack eye contact.

Polanczyk adds that the medical community is still concerned about offering treatment and interventions to those diagnosed.

"Broadly disseminating a diagnostic tool throughout the community without further training for professionals and appropriate interventions for children with autism or other conditions could potentially cause harm," he explains.

He further notes that the ability to assess each individual's genetic risk and how much it contributes to diagnosis is likely a biomarker with greater potential than eye contact. Furthermore, artificial intelligence technologies, which allow for the processing of vast amounts of data, will certainly contribute to more accurate diagnosis.

Pediatric neurologist Carlos Gadia, an expert on the subject, spoke with Bem-Estar and explained the signs of ASD. He emphasized that the idea that each child develops at their own pace is valid within the limits of normality:

"We know that some children start talking at seven or eight months and others who start talking at 16 months. But a 3-year-old child who isn't communicating is always abnormal," he says.

According to the doctor, cases where 12-month-olds still don't wave, don't respond when called by name, or don't smile should be investigated. The same applies to children at any age who show regression—that is, lose skills they had previously acquired.

The basis of treatment for ASD involves behavioral and speech-language interventions, with a focus on language development.

Gadia emphasizes that parents and family members play an essential role in treatment and warns against the idea that there is an "expiration date" for development:

"Nothing will happen without the family's participation. Don't accept any kind of therapy in which they are relegated to the role of spectator—like: I'll pick up my child, leave him there, and leave. And this idea that, at some point, the brain's developmental windows close and there's no point in doing anything anymore is absolutely wrong."

The SUS offers care to people with Autism Spectrum Disorder through the Care Network for People with Disabilities, which has 577 units across the country.

An IBGE survey showed that 2.4 million people were diagnosed with ASD in Brazil — the equivalent of just over 1% of the population.

Among children , data from American researchers indicate that one in 31 lives with a developmental disorder.