Abstract:

PURPOSE: To investigate the changes of resting-state interhemispheric functional connectivity in the brain of the ametropic amblyopia patients.
METHODS: 13 ametropic amblyopia patients (age: 11-16years) and 10 normal controls (ages: 11-16 years) were recruited for the study. The functional magnetic resonance imaging (fMRI) images of both normal controls and ametropic amblyopia patients were obtained in Beijing Tongren Hospital and preprocessed. And then, voxel-mirrored homotopic connectivity (VMHC) method was used to assess the homotopic resting-state functional connectivity (RSFC), which is a sensitive index for detecting the inter-hemispheric alterations of the amblyopia. Group comparisons were conducted and Pearson correlations were used to explore the correlationship between mean VMHC values in the abnormal regions and the clinical parameters.
RESULTS: We performed two-tailed two sample t test to assess the differences of VMHC between amblyopia patients and normal controls. As we used the symmetric T1 mash, the result showed symmetric abnormal regions in the brain. Amblyopia patients exhibited decreased VMHC in middle temporal gyrus (MTG), inferior temporal gyrus (ITG), precuneus, precentral gyrus (PreCG), posterior cingulate gyrus (PCG) and supplementary motor area (SMA) regions. Meanwhile, the increased VMHC were located in the insula and putamen. The Pearson correlation analysis showed that the mean VMHC values in MTG were positively correlated (r = 0.728, p = 0.011) with the visual acuity in amblyopia patients.
CONCLUSIONS: Significant differences between amblyopia patients and normal controls in VMHC showed that the alterations of inter-hemispheric functional connectivity in the brain, indicating the changes of the inter-hemispheric coordination and functional homotopy in amblyopia.

Key words: amblyopia, fMRI, VMHC