GABAergic inhibition in the visual cortex of children before and after amblyopia therapy

Amblyopia is the most common vision disorder in children. It is marked by chronically reduced vision in one eye, possibly due to abnormal visual suppression. We aim to test whether GABAergic inhibition in the visual cortex is involved in abnormal visual suppression in childhood amblyopia. To achieve this, we will apply magnetic resonance spectroscopy to characterise GABAergic inhibition in the early visual cortex of up to 35 children with amblyopia and 35 age and sex-matched, normally sighted, controls. Amblyopes will visit once immediately after their diagnosis of amblyopia, and early in their standard amblyopia therapy and again either immediately after conclusion of their therapy or after six months, whichever comes first. On each visit, identical vision tests (visual acuity, contrast sensitivity, stereopsis) and magnetic resonance imaging (MRI) measures (T1-weighted structural scan, magnetic resonance spectroscopy, resting state functional MRI) will be collected. Control participants will be matched to the visit interval of the amblyopes, with no intervention between visits. Our hypothesis is that GABA in the early visual cortex will differ in amblyopes compared to controls, and that change in GABA after amblyopia therapy will relate to improvements in vision. Overall, our work aims to provide insights into the neural substrates of amblyopia in children and, by doing so, advance understanding of heightened neuroplasticity in childhood.