Poor visual fixation in children and its possible role in attention deficit disorder (ADD)

Associations between Attention-Deficit/Hyperactivity Disorder and Ocular Abnormalities in Children: A Population-based Study

Purpose: Attention-deficit/hyperactivity disorder (ADHD) was reported to be associated with disturbances in the prefrontal circuitry and seems to be associated with dysfunctions of eye motility. This study aimed to explore associations between ADHD and ocular abnormalities, including amblyopia, hypermetropia, astigmatism, and heterotropia, using a large, nationwide population-based dataset in Taiwan.Methods: We retrieved our sample for this cross-sectional study from the Taiwan National Health Insurance Research Database. In total, 116,308 children with ADHD were selected as the study group and 116,308 randomly selected children without ADHD as the comparison group. We used conditional logistic regression analyses to examine the odds ratios (ORs) of amblyopia, hypermetropia, astigmatism, and heterotropia between children with and those without ADHD.Results: We found that children with ADHD had significantly higher prevalences of amblyopia (1.6% vs. 0.9%, p< .001), hypermetropia (2.4% vs. 1.3%, p < .001), astigmatism (0.2% vs. 0.1%, p < .001), and heterotropia (1.1% vs. 0.5%, p < .001) than children without ADHD. The ORs of amblyopia, hypermetropia, astigmatism and heterotropia for children with ADHD were 1.89 (95% confidence interval (CI) = 1.76 ~ 2.05), 1.82 (95% CI = 1.68 ~ 1.92), 1.73 (95% CI = 1.34 ~ 2.16), and 2.01 (95% CI = 1.82 ~ 2.21) compared to children without ADHD.Conclusions: The findings suggest that ADHD is associated with ocular abnormalities, including amblyopia, hypermetropia, astigmatism, and heterotropia.

Comparison of change detection performance and visual search patterns among children with/without ADHD: Evidence from eye movements

BACKGROUND

ADHD participants showed poorer change detection performance compared to participants without any diagnosis. The difficulty to detect changes in ADHD children might be due to their voluntary eye movement control and attentional deficits.

AIMS

To evaluate change detection performance and visual search patterns of children with ADHD and compare their performances with typically developing (TD) children.

METHODS AND PROCEDURES

48 children (nADHD=24, nTD=24) participated (Mage=8 years, 10 months). Flicker paradigm was used to evaluate change detection performance, while eye movements were recorded during the experiment.

RESULTS

Change detection accuracies of TD children were higher compared to ADHD children. TD groups made longer fixations on the changed area and their first fixation duration was also longer than ADHD children which showed that TD children had longer fixation maintenance than ADHD children.

CONCLUSIONS

The change detection performance, which is associated with visual attention and memory, was found to be worse in ADHD children than TD children and these children made shorter fixations on the changed area than TD children. The findings were found to be in line with the difficulty to sustain attention in ADHD children that is necessary for encoding the scene properties and goal-oriented behavior.