A Resting-state FMRI Study Of Network Functional Connectivity Changes In Children With Anisometropic Amblyopia

Purpose: Amblyopia is generally considered as a neurodevelopmental visual impairment,characterized by poor visual acuity,contrast and spatial sensitivity,resulting from abnormal visual experiences during early childhood.In recent years,several studies have observed morphological changes in gray and white matter in amblyopia,as well as the functional connectivity changes.Even though,the effect of amblyopia on brain functional and its neural mechanisms are still remain unclear.This study is the first combining FC analyses with multivariate pattern analysis(MVPA)to investigate the alteration of intra-and inter-network resting state functional connectivity(rs FC)in children with amblyopia,providing an experimental basis for further understanding the effects of amblyopia on brain function and its neural mechanisms.Materials and Methods: Sixteen(16)right-handed children with anisometropic amblyopia(AAC)aged 5-15 and eleven(11)age-matched,right-handed,normal sight children(NSC)were recruited.Patients with monocular anisometropic amblyopia exhibited visual acuity ≤ 0.6 in the amblyopic eye and visual acuity ≥ 0.9 in the unaffected eye.After preprocessing,the participants with excessive head motion were excluded,resulting in the f MRI data of 14 AAC(11 males,3 females;age: 9.67 ± 2.9 years)and 9 NSC(6 males,3 females;age: 11.37 ± 2.9 years).This study consists of three parts.Part I: using voxel-based functional connectivity analyses,network seed-to-whole brain voxels correlation maps of the dorsal attention network(DAN),default mode network(DMN),frontoparietal control network(FPCN),ventral attention network(VAN)and visual network(VN)for each participant were obtained.Then,the searchlight MVPA was performed to detect the brain regions that can discriminate the rs FC of network seeds between the AAC and NSC groups.Furthermore,the changes of rs FC in the AAC group were investigated.Then,within and between the network rs FC were also investigated.Part II: the resulting regions of searchlight MVPA were used as regions of interest(ROIs)to calculate the pearson correlation coefficient among ROIs for the AAC and NSC groups.Then,the correlation coefficient were used as features in theweight-based feature selection MVPA to identify the consensus connections that can be used to distinguish the AAC and NSC groups.Moreover,the specific changes of consensus connections in the AAC group were investigated.Then,the changes of rs FC within and between the networks to which the consensus connections belong were analyzed.Part III: the whole brain were parcellated into 512 ROIs according to the automated anatomical labeling(AAL)to calculate the pearson correlation coefficient among ROIs for the AAC and NSC groups.Then,weight-based feature selection MVPA were performed to identify the consensus connections.After that,the changes of consensus connections in the AAC group were investigated.Results: MVPA was able to successfully classify the rs FC between the AAC and NSC groups.Further,the rs FCs were changed within the DMN,DAN and VAN,and between the DMN with the FPCN,DAN,VAN and SMN,as well as between the VAN with subcortical regions in AAC.Moreover,compared with the NSC group,the AAC group consistently displayed decreased rs FC within the DMN,as well as between the DMN with the FPCN and DAN.In addition,the MFG.R of the FPCN exhibited the highest functional contribution for classifying the AAC and NSC groups.Conclusions: 1.The decreased rs FC within the DMN in the AAC group indicates that the abnormalities of spontaneous cognitive function may exist in AAC.2.The decreased rs FC between the DMN with FPCN and DAN in the AAC group may indicate a reduced ability in amblyopia to transform and mediate the dynamic balance between internally and externally goal-directed cognition.3.The MFG.R exhibited the highest weight for classifying the AAC and NSC groups,indicating that the mark role of MFG.R in brain function changes in AAC.4.The low visual function of AAC not only affects the effective transmission of information in the visual system,but also affects the transmission,regulation,and conversion of information within and between the visual cognitive related network.