Comparative study of interhemispheric functional connectivity in left eye monocular blindness versus right eye monocular blindness: a resting-state functional MRI study

// Yi Shao 1, * , Jing Bao 1, * , Xin Huang 1, 2 , Fu-Qing Zhou 3 , Lei Ye 1 , You-Lan Min 1 , Lin Yang 1 , Zubin Sethi 4 , Qing Yuan 1 and Qiong Zhou 1 1 Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi, China 2 Department of Ophthalmology, The People's Hospital of Hubei Province, Wuhan 430060, Hubei, China 3 Department of Radiology, The First Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi, China 4 University of Miami, Miami, Florida 33146, USA * These authors contributed equally to this work Correspondence to: Qiong Zhou, email: 375135747@qq.com Keywords: monocular blindness; voxel-mirrored homotopic connectivity; resting state; functional magnetic resonance imaging Received: December 05, 2017      Accepted: January 25, 2018      Epub: February 14, 2018      Published: March 06, 2018 ABSTRACT Objective: In the present study, we investigated the brain interhemispheric functional connectivity changes in left eye MB versus right eye MB patients by voxel-mirrored homotopic connectivity (VMHC) methods. Methods: A total of 31 patients with MB (15 with left eye MB and 16 with right eye MB), and 31 healthy controls (HCs) closely matched for age were recruited. All subjects underwent functional magnetic resonance imaging (fMRI) examinations. The VMHC method was used to evaluate directly functional interactions between the hemispheres. A one-way ANOVA was performed to determine the regions in which the VMHC differs between the three groups. Patients with MB were distinguished from HCs by a receiver operating characteristic (ROC) curve. The relationships between the mean VMHC signal values in many brain regions and clinical features in MB patients were calculated by pearson correlation analysis. Results: Compared with HCs, MB patients had significantly decreased VMHC values in the cuneus/calcarine/lingual gyrus. Furthermore, left eye MB showed decreased VMHC values in the cuneus/calcarine/lingual gyrus and showed increased VMHC values in the insula and middle frontal gyrus compared with HC. In addition, right eye MB showed decreased VMHC values in the cuneus/calcarine/lingual gyrus, primary motor cortex (M1)/primary somatosensory cortex (S1) and superior parietal lobule. Conclusion: MB subjects showed abnormal brain interhemispheric functional connectivity in visual pathways. Furthermore, different patterns of brain interhemispheric functional connectivity occurred in the left eye and right eye MB. These VMHC values provide much useful information to explain the neural mechanism changes in MB.