Brief report: effects of methylphenidate on the light adapted electroretinogram

Purpose: To explore changes in the electroretinogram (ERG) following methylphenidate use in attention-deficit/hyperactivity disorder (ADHD).

Methods: Light adapted ERGs were recorded in five individuals (3 male and 2 female, age range 13.6-21.8 years) with a diagnosis of ADHD. Six flash strengths ranging from 71 to 446 Td.s were qualitatively evaluated following a minimum of 24 h without any medication and from 2 to 6 h following the individuals' standard slow-release (XL) methylphenidate dose that ranged from 18 to 60 mg.

Results: Of the six flash strengths, the 178 Td.s strength revealed changes in four of the five participants with a median 27.4% increase in b-wave amplitude. For three individuals there was an increase in the a-wave amplitude and for two of the same individuals there was also a noticeable pronouncement of the oscillatory potentials. The a-wave amplitude showed a greatest median increase at the 446 Td.s flash strength of 25.8%. One individual - on the highest dose (60 mg) exhibited no morphologically distinct changes in the ERG. No differences in the time to peaks of the a- and b-wave were observed for any individual.

Conclusion: The a- and b-wave amplitudes of the light adapted ERG could provide insights into the effect of methylphenidate in ADHD.