The effects of methylphenidate on refraction and anterior segment parameters in children with attention deficit hyperactivity disorder.

BACKGROUND: Methylphenidate hydrochloride is used as first-line treatment for attention deficit hyperactivity disorder (ADHD). However, there is concern that this treatment may be associated with increased risk of angle closure glaucoma and disturbance of ocular refraction. The aim of this study was to investigate the effects of methylphenidate treatment on refraction, intraocular pressure, and the anterior chamber in children with ADHD.
METHODS: In this prospective pilot study, children diagnosed with ADHD were examined before the start of methylphenidate treatment and again 3 and 9 months after the start of treatment. Ocular examination before and after cycloplegia was performed at each visit, including Pentacam imaging of the anterior chamber.
RESULTS: A total of 14 patients (mean age, 11 years) were recruited. The mean visual acuity, sphere, spherical equivalent refraction, intraocular pressure, and cup:disk ratio did not change significantly after the start of treatment. The anterior chamber depth after cycloplegia decreased significantly between baseline and 9 months, from 3.26 ± 0.22 mm to 3.24 ± 0.23 mm in the right eye (P = 0.037) and from 3.28 ± 0.22 mm to 3.25 ± 0.24 mm in the left eye (P = 0.001).
CONCLUSIONS: Methylphenidate does not seem to affect refraction in most children with ADHD. After 9 months of treatment, however, there was a reduction in the anterior chamber depth, which has been described as a powerful predictor of angle closure glaucoma. Further investigation of the potential ocular side effects of methylphenidate treatment is warranted.