Findings from a new study identify a link between pupillary light reflex (PLR) and later autism diagnosis, with its authors suggesting pupillometry could possibly facilitate risk assessment in infants.
The study included 187 children of which 147 infants had an older sibling with autism and of whom 29 met criteria for autism at follow-up. The study also included a control group consisting of 40 infants from the general population. PLR was examined at 9-10 months and the individuals were followed until three years, when the diagnostic evaluation was conducted.
The authors found that on average, the relative constriction of the PLR was larger in 9–10-month-old high-risk infant siblings who receive an autism spectrum disorder (ASD) diagnosis at 36 months, compared both to those who do not and to low-risk controls. Furthermore, the magnitude of the PLR in infancy was associated with symptom severity at follow-up.
Presenting the findings in Nature Communications, the authors said the study indicates an important role of sensory atypicalities in the aetiology of ASD.
They also highlighted how other and larger studies of infants at risk are ongoing and said that these studies “may illuminate whether the PLR is useful for defining sub-groups within the ASD population”.