Structural MRI alterations in children with form-deprivation amblyopia: a propensity score-matched case-control study

AIMS: Form-deprivation amblyopia (FDAM) is a severe neurodevelopmental disorder from early visual deprivation. This study uses T1-weighted MRI to explore its neuroanatomical correlates. METHODS: 18 Chinese children with bilateral FDAM and 36 propensity score-matched healthy Chinese controls (1-to-2 matched for age, sex and mean cortical thickness) underwent 3.0T T1-weighted MRI (1×1×1 mm³ resolution). Cortical and subcortical structures were parcellated using FreeSurfer V.7.3.2 with multiatlas (Desikan-Killiany-Tourville, Destrieux, subset Brodmann and Aseg), alongside specialised modules for thalamic nuclei and hippocampal-amygdala subfields. Linear regression models adjusted for age and sex were employed for group comparisons with Bonferroni correction. RESULTS: FDAM exhibited widespread structural alterations: Primary visual deficits included right V1 thinning (p=3.60×10⁻⁴) and pericalcarine atrophy (p=1.03×10⁻⁷), with subcortical degeneration in bilateral lateral geniculate (p≤1.77×10⁻⁵) and pulvinar nuclei (p≤2.67×10⁻⁴). Language networks showed left BA44/45 atrophy (Broca's area, p≤9.19×10⁻⁹) and bilateral thinning of planum temporale (critical for auditory language, p≤9.11×10⁻⁶). Disruptions in somatosensory and cross-modal integration regions were observed, such as in somatosensory processing, as manifested by bilateral atrophy in BA3a (p≤2.62×10⁻⁴) and left BA3b (p=1.86×10⁻⁴). The cognitive control networks also exhibited thinning (eg, left inferior frontal sulcus, p=1.05×10⁻⁸). Subcortically, volume loss affected bilateral globus pallidus (p≤1.24×10⁻⁷) and thalamic nuclei (p≤1.11×10⁻⁴) and amygdalar substructures (eg, left central nucleus: p=1.22×10⁻⁷). CONCLUSION: FDAM involves multisystem neural disruptions spanning primary visual, language, somatosensory, cognitive and emotion-regulation networks. These findings highlight the disorder's complexity and motivate further mechanistic studies.