Effect of methylphenidate as a dopaminergic agent on myopia: Pilot study

Background Methylphenidate (MPH) hydrochloride is used as a first-line treatment for attention deficit hyperactivity disorder (ADHD). However, there is concern that this treatment may be associated with increased risk of refractive disorder. The aim of this study was to investigate the effect of MPH therapy on myopic shifts in refraction in children diagnosed with ADHD. Methods This study, children with ADHD and meeting inclusion criteria were examined before the initiation of MPH treatment and 3, 6 and 12 months after the initiation of treatment. Twenty age-gender-matched participants who applied to the outpatient ophthalmology clinic with various complaints were included in the study as a control group. Cycloplegic refraction examination and detailed eye measurements were performed at each visit. Results Nineteen patients were included in this study and the group consisted of 11 (57.9%) females and 8 (42.1%) males. The mean age of patients was 11.3 ± 2. (range: 8-18) years. During 12 months of use of MPH, the spherical equivalent changed from -0.36 ± 1.08 to -0.39 ± 1.05, and this difference was not statistically significant (P = .187). Axial length ranged from 22.92 ± 0.66. There was a change to 22.93 ± 0.62, and this difference was not statistically significant (P = .076). In the control group, the spherical equivalent changed from -0.43 ± 0.62 to -0.56 ± 0.84, and this difference was statistically significant. (P = .012) There was a change in the axial length from 22.97 ± 0.78 to 22.99 ± 0.62, and this difference was statistically significant (P = .015). Conclusions No significant changes spherical equivalent and axial length were detected during 12-month MPH use, but the increased spherical equivalent and axial length in the control group in the similar age group may indicate that MPH may reduce myopic shifts in refraction progression through dopamine, similar to in vivo studies. What's known Myopia is spreading rapidly in technologically advanced societies. There is strong evidence that myopia develops as the axial length of the eye increases as a result of spending more time indoors and working in close distances in parallel with the increase in education level. Animal studies have shown that decreased dopamine release plays an important role in the development of myopia. What's new The effect of dopamine in slowing or stopping myopia in experimental studies has also been demonstrated in human studies. No significant change in spherical equivalent and axial length was observed in methylphenidate users compared with control patients of similar age group. A significant increase in spherical equivalent and axial length was detected in the control group. This pilot study will shed light on future studies on the safe use of dopamine in the treatment of myopic shifts.