The possible association of attention deficit hyperactivity disorder with undiagnosed refractive errors

To evaluate whether attention deficit disorder (ADD) or attention deficit with hyperactivity disorder (ADHD) is associated with undiagnosed refractive errors or binocular function difficulties.

In this case-control study, ADD/ADHD children diagnosed according to criteria of the Diagnostic and Statistical Manual of Mental Disorders (DSM IV-TR), along with age-matched controls, were examined at the ADD clinic at the Sheba Medical Center. For children in both groups the following data were recorded: uncorrected visual acuity for distance and near, cycloplegic refraction, ocular motility, and binocular function.

A total of 56 children (12 girls; mean subject age, 9.5 years) were included in the ADD/ADHD group. The control group comprised 66 patients (29 girls; mean subject age, 9 years). Mean uncorrected visual acuity was nearly 20/20 for distance and J1 for near in both groups. Cycloplegic spherical equivalent was +0.89 ± 1.1 D for the control group and +0.63 ± 0.89 D for the ADD/ADHD group (P = 0.16). Binocular function and accommodation were similar in both groups, except for a significant difference between the near point of convergence of the controls versus the ADD/ADHD group (5.3 ± 2.3 cm versus 4.1 ± 1.8 cm, respectively; P = 0.002).

ADD/ADHD children had similar visual acuity at distance and near and refractive errors as normal subjects. Binocular function and accommodation were also found to be similar in both groups and thus might not contribute to ADD/ADHD.