Abstract
BACKGROUND: Autism spectrum disorder (ASD) often presents with atypical visual processing, prompting investigation into its connection with retinal features. This study aimed to (I) compare intraretinal layer thickness in the peripapillary region between ASD and neurotypical (NT) groups, (II) assess associations between intraretinal layer thickness and clinical parameters (social functioning and cognitive levels) in ASD subjects, and (III) evaluate the potential of intraretinal layer thickness as a biomarker for ASD. METHODS: Participants were recruited through convenience sampling from the Children's Mental Health Research Center at The Affiliated Brain Hospital of Nanjing Medical University and the Department of Ophthalmology at The First Affiliated Hospital of Nanjing Medical University, Nanjing, China, between December 2019 and August 2023. Intraretinal layer thickness in peripapillary region was quantified using optic coherence tomography images with automated layer segmentation performed by OCTExplorer software on 47 individuals with ASD (aged 7-13 years) and age- and sex-matched NT controls. Inter-group comparisons were conducted using unpaired t-tests, Welch's t-tests, or Mann-Whitney U tests as appropriate. Correlations with social functioning (measured by Social Responsiveness Scale scores) and cognitive levels [measured by total intelligence quotient (IQ) scores] were examined using the Spearman correlation coefficient. Stepwise regression analysis was conducted to assess predictive power. RESULTS: Significant inter-group differences (P<0.05) were observed in ganglion cell layer and inner nuclear layer (INL) thickness across global and specific quadrant regions. Participants had a mean age of 9.57±1.83 years in the ASD group and 9.89±1.70 years in the age-matched NT group. While no correlation was found between retinal sublayer thickness and social functioning on ASD subjects (all P>0.05), there was a notable correlation between INL thickness in the infero-nasal quadrant and cognitive level (r=0.381, P=0.014). Stepwise regression analysis identified global INL thickness as a significant predictor of total IQ scores (β=3.986, P=0.034), with an R(2) of 0.110 and a root mean square error of 21.900. CONCLUSIONS: This study highlights significant differences in retinal features between ASD and NT groups, with implications for understanding ASD pathogenesis and complexity. The findings suggest that easily observable retinal features hold promise as biomarkers for ASD, warranting further investigation.