Effect of Levodopa on Human Multifocal Electroretinogram
Status:
Completed
Trial end date:
2003-10-01
Target enrollment:
Participant gender:
Summary
It is known that dopamine is a functional neuromodulator at several levels of the visual
system. Dopamine seems to be involved in the organization of the ganglion cell and the
bipolar cell receptive fields and modulation of physiological activity of photoreceptors.
There is evidence for the functional significance of dopaminergic modulation of visual
sensitivity in humans which confirms the hypothesis that dopamine plays an important role in
retinal light adaptation as well as in motion and contrast sensitivity function. The
electrophysiological effects of dopamine, various dopamine antagonist and levodopa in animals
and humans have been investigated by means of visual evoked potentials and
electroretinograms. The multifocal ERG technique, developed by Sutter et al. allows a rapid,
simultaneous recording of focal ERGs from multiple retinal locations. Although this technique
is relatively new, it has already provided insights into the mechanisms of retinal diseases
(e.g. involvement of visual system in Parkinson disease), but until now there is no data on
influence of dopaminergic substances on mERG.