Accommodative response in children with attention deficit hyperactivity disorder (ADHD): the influence of accommodation stimulus and medication

Background There are claims that ocular accommodation differs in children with attention deficit hyperactivity disorder (ADHD) compared to typically developing children. We examined whether the accommodation response in ADHD children is influenced by changing the stimulus to accommodation in an attempt modify the level of attentional engagement or by medication for the condition. Methods We measured the accommodative response and pupil diameter using a binocular, open-field autorefractor in non-medicated and medicated children with ADHD ( n = 22, mean age = 10.1 ± 2.4 years; n = 19; mean age = 11.0 ± 3.8 years; respectively) and in an age-matched control group ( n = 22; mean age = 10.6 ± 1.9 years) while participants were asked to maintain focus on (i) a high-contrast Maltese cross, (ii) a frame of a cartoon movie (picture) and (iii) a cartoon movie chosen by the participant. Each stimulus was viewed for 180 s from a distance of 25 cm, and the order of presentation was randomised. Results Greater lags of accommodation were present in the non-medicated ADHD in comparison to controls ( p = 0.023, lags of 1.10 ± 0.56 D and 0.72 ± 0.57 D, respectively). No statistically significant difference in the mean accommodative lag was observed between medicated ADHD children (lag of 1.00 ± 0.44D) and controls ( p = 0.104) or between medicated and non-medicated children with ADHD ( p = 0.504). The visual stimulus did not influence the lag of accommodation ( p = 0.491), and there were no significant group-by-stimulus interactions ( p = 0.935). The variability of accommodation differed depending on the visual stimulus, with higher variability for the picture condition compared to the cartoon-movie ( p