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A longitudinal study of pupillary light reflex in 6- to 24-month children
Clare Kercher1, Leila Azinfar1, Dinalankara M R Dinalankara1,2
1Department of Biomedical, Biological & Chemical Engineering, University of Missouri, Columbia, MO, 65211, USA.
Insights
Infants and toddlers show age-related changes in pupillary light reflex (PLR). Children at high risk for autism spectrum disorder (ASD) exhibit distinct PLR patterns compared to low-risk children.
Area of Science:
- Neuroscience
- Developmental Psychology
- Ophthalmology
Background:
- Pupillary light reflex (PLR) is an involuntary pupil response to light.
- Altered PLR has been observed in children with autism spectrum disorders (ASDs).
- PLR in infants and toddlers remains an understudied area.
Purpose of the Study:
- To investigate age-related changes in PLR in infants and toddlers (6-24 months).
- To examine differences in PLR between infants with high and low familial risk for ASDs.
Main Methods:
- Longitudinal study design.
- Remote pupillography used to measure PLR parameters.
- Participants categorized into high-risk (HR) and low-risk (LR) groups based on ASD family history.
Main Results:
- Significant age effects observed in resting pupil radius, minimal pupil radius, relative constriction, latency, and response time.
- HR group showed significantly larger resting and minimal pupil sizes compared to the LR group.
- Distinct PLR characteristics were identified in infants with higher ASD risk.
Conclusions:
- PLR undergoes significant age-related development in infants and toddlers.
- Infants with a higher familial risk for ASD exhibit altered pupillary responses.
- PLR may serve as a potential early indicator for neurodevelopmental differences.
Abstract:
Pupillary light reflex (PLR) is an involuntary response where the pupil size changes with luminance. Studies have shown that PLR response was altered in children with autism spectrum disorders (ASDs) and other neurological disorders. However, PLR in infants and toddlers is still understudied. We conducted a longitudinal study to investigate PLR in children of 6-24 months using a remote pupillography device. The participants are categorized into two groups. The 'high risk' (HR) group includes children with one or more siblings diagnosed with ASDs; whereas the 'low risk' (LR) group includes children without an ASD diagnosis in the family history. The participants' PLR was measured every six months until the age of 24 months. The results indicated a significant age effect in multiple PLR parameters including resting pupil radius, minimal pupil radius, relative constriction, latency, and response time. In addition, the HR group had a significantly larger resting and minimal pupil size than the LR group. The experimental data acquired in this study revealed not only general age-related PLR changes in infants and toddlers, but also different PLRs in children with a higher risk of ASD.
