Article

Amblyopia is a neurodevelopmental disorder of vision that is
associated with abnormal patterns of neural inhibition within the visual cortex.
This disorder is often considered to be untreatable in adulthood because of
insufficient visual cortex plasticity. There is increasing evidence that
interventions that target inhibitory interactions within the visual cortex,
including certain types of noninvasive brain stimulation, can improve visual
function in adults with amblyopia. OBJECTIVE: We tested the hypothesis that
anodal transcranial direct current stimulation (a-tDCS) would improve visual
function in adults with amblyopia by enhancing the neural response to inputs from
the amblyopic eye. METHODS: Thirteen adults with amblyopia participated and
contrast sensitivity in the amblyopic and fellow fixing eye was assessed before,
during and after a-tDCS or cathodal tDCS (c-tDCS). Five participants also
completed a functional magnetic resonance imaging (fMRI) study designed to
investigate the effect of a-tDCS on the blood oxygen level-dependent response
within the visual cortex to inputs from the amblyopic versus the fellow fixing
eye. RESULTS: A subgroup of 8/13 participants showed a transient improvement in
amblyopic eye contrast sensitivity for at least 30 minutes after a-tDCS. fMRI
measurements indicated that the characteristic cortical response asymmetry in
amblyopes, which favors the fellow eye, was reduced by a-tDCS. CONCLUSIONS: These
preliminary results suggest that a-tDCS deserves further investigation as a
potential tool to enhance amblyopia treatment outcomes in adults.

Langue : ANGLAIS