Oculomotor deficits in attention deficit hyperactivity disorder: a systematic review and meta-analysis

There is equivocal evidence on the presence of oculomotor deficits among children with attention deficit hyperactivity disorder (ADHD), which can be an additional challenge in this population, especially with reading-related tasks. This study aimed to review the deficits in the oculomotor parameters among children with ADHD compared with age-matched controls. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A search of original research articles on various databases was done using key terms, such as "oculomotor deficit," "attention deficit hyperactivity disorder," or related terms. We included case-control studies and excluded studies in which children received medications during the test. Twelve original research studies were considered for this review. Ten studies reported data on various types of saccades, two studies reported data on fixation, and one study reported data on pursuit. Among various oculomotor deficits, the forest-plot analysis of an antisaccade task showed that children with ADHD made more direction errors compared to controls. Although independent studies report that ADHD children have poorer performance compared to control populations during oculomotor tasks, there is a lack of evidence to draw a strong conclusion. Children with ADHD are less precise in performing eye movements and need more time to complete the oculomotor tasks than those without ADHD. The overall results provide minimal evidence regarding the presence of various oculomotor deficits in ADHD.