Optical Coherence Tomography Measurements of Retina and Choroid in Autism Spectrum Disorder: A Systematic Review and Meta-Analysis.

Researchers used special eye scans (OCT) to compare the back of the eye in 373 people with autism versus 443 people without autism across 10 studies. They found that most measurements were the same between groups, but one small area at the back of the eye was slightly thicker in people with autism. This might reflect differences in brain development, but more research is needed to understand what this means and whether it could be useful for diagnosis or understanding autism.

This systematic review and meta-analysis examined optical coherence tomography (OCT) measurements in 373 individuals with autism spectrum disorder compared to 443 neurotypical controls across 10 studies. OCT is a non-invasive imaging technique that measures retinal layer thickness, potentially serving as a biomarker for neurodevelopmental differences. The analysis found no significant differences in most retinal measurements, including macular layers and most regions of the peripapillary retinal nerve fiber layer. However, one specific region - the inferonasal portion of the peripapillary retinal nerve fiber layer - was significantly thicker in individuals with ASD.

While this suggests subtle neurodevelopmental differences may be detectable through eye imaging, the clinical significance remains unclear given the localized nature of the finding.

Current evidence does not support OCT as a reliable diagnostic biomarker for autism. The localized retinal differences observed may reflect subtle neurodevelopmental variations but require larger, more standardized studies to determine clinical utility and significance.

Small sample sizes across studies, methodological differences between research groups, and potential confounding factors limit the reliability of findings. The clinical significance of the observed differences remains unclear.

<p>Introduction: The purpose of this systematic review and meta-analysis was to compare optical coherence tomography (OCT) retinal measurements between patients with autism spectrum disorder (ASD) and the neurotypical controls, exploring the potential of OCT as a noninvasive biomarker for ASD-related neurodevelopmental alterations. PubMed, Embase, and Scopus databases were explored to determine eligible articles reporting OCT measurements of the retina and choroid in patients with ASD compared to healthy controls. Statistical analysis of OCT metrics was performed if reported in at least three discrete studies. In the process, fixed- and random-effects models were utilized, depending on the heterogeneity level between studies.

Subgroup analysis based on the age group of cases, the method of eye selection, age and sex matching of cases and controls, and the OCT device used was also conducted. Ten studies with 373 ASD cases (with a total of 640 eyes) and 443 controls (with a total of 760 eyes) were included in this study. No significant alteration was observed in the average total macular layer, macular inner nuclear layer (INL), macular inner plexiform layer (IPL), macular ganglion cell layer (GCL), and macular retinal nerve fiber layer (RNFL) thickness. There was also no significant difference in the peripapillary retinal nerve fiber layer (pRNFL) thickness of the eyes of cases with ASD compared to healthy controls, except for the inferonasal portion of the pRNFL, which was significantly thicker in ASD subjects when compared to controls (p = 0.02).

The findings of the present meta-analysis indicate a localized thickening of the inferonasal pRNFL with no alteration of other portions of pRNFL and macular layers (IPL, INL, GCL, RNFL). Although OCT may reflect subtle neurodevelopmental differences in ASD, current evidence is limited by small sample sizes, methodological heterogeneity, and potential confounders. </p>.