Xiaohe Yan1,2, Yun Wang3,4,5, Lijuan Xu6,7, Yong Liu6,7, Shaojie Song8, Kun Ding8, Yuan Zhou5, Tianzi Jiang6,7, Xiaoming Lin8. 1. b Shenzhen Key Laboratory of Ophthalmology , Shenzhen Eye Hospital , Jinan University, Shenzhen , China. 2. c School of Optometry , Shenzhen University , Shenzhen , China. 3. d The National Clinical Research Center for Mental Disorders & Beijing Key Laboratory of Mental Disorders , Beijing Anding Hospital , Capital Medical University, Beijing , China. 4. e Advanced Innovation Center for Human Brain Protection , Capital Medical University , Beijing , China. 5. f Key Laboratory of Behavioral Science & Magnetic Resonance Imaging Research Center , Institute of Psychology, Chinese Academy of Sciences , Beijing , China. 6. g Brainnetome Center , Institute of Automation, Chinese Academy of Sciences , Beijing , China. 7. h National Laboratory of Pattern Recognition , Institute of Automation, Chinese Academy of Sciences , Beijing , China. 8. a State Key Laboratory of Ophthalmology , Zhongshan Ophthalmic Center, Sun Yat-sen University , Guangzhou , China.
Abstract
PURPOSE: The aim of this study was to examine the functional connectivity between the primary visual cortex and other cortical areas during rest in normal subjects and patients with comitant strabismus using functional magnetic resonance imaging (fMRI). METHODS: A prospective, observational study was conducted. Ten patients with comitant exotropia and eleven matched healthy subjects underwent resting-state fMRI with their eyes closed. Resting-state fMRI was performed using a 3.0 T MR scanner. The primary visual cortex was subdivided into anterior and posterior subdivisions. The resting-state functional connectivities within the primary visual cortex and between the primary visual cortex and other cortical areas were calculated for each group and compared between the strabismic and normal control groups. fMRI data were analyzed using Statistical Parametric Mapping software and Analysis of Functional NeuroImages software. RESULTS: Compared with the normal controls, patients with comitant strabismus had increased functional connectivity between the posterior primary visual cortex and other cortical areas, especially the visual cortex [Brodmann area 19 (BA19)] and other oculomotor regions, such as the frontal eye field (BA6). CONCLUSIONS: The fMRI results suggest that ongoing and permanent cortical changes occur in patients with comitant strabismus. Disrupted brain functional connectivities are associated with abnormal eye movement and loss of stereopsis. Our study provides a neurological basis for understanding the pathophysiology of comitant strabismus, which may prompt new areas of research to more precisely define this basis and extend these findings to enhance diagnosis and treatment.
PURPOSE: The aim of this study was to examine the functional connectivity between the primary visual cortex and other cortical areas during rest in normal subjects and patients with comitant strabismus using functional magnetic resonance imaging (fMRI). METHODS: A prospective, observational study was conducted. Ten patients with comitant exotropia and eleven matched healthy subjects underwent resting-state fMRI with their eyes closed. Resting-state fMRI was performed using a 3.0 T MR scanner. The primary visual cortex was subdivided into anterior and posterior subdivisions. The resting-state functional connectivities within the primary visual cortex and between the primary visual cortex and other cortical areas were calculated for each group and compared between the strabismic and normal control groups. fMRI data were analyzed using Statistical Parametric Mapping software and Analysis of Functional NeuroImages software. RESULTS: Compared with the normal controls, patients with comitant strabismus had increased functional connectivity between the posterior primary visual cortex and other cortical areas, especially the visual cortex [Brodmann area 19 (BA19)] and other oculomotor regions, such as the frontal eye field (BA6). CONCLUSIONS: The fMRI results suggest that ongoing and permanent cortical changes occur in patients with comitant strabismus. Disrupted brain functional connectivities are associated with abnormal eye movement and loss of stereopsis. Our study provides a neurological basis for understanding the pathophysiology of comitant strabismus, which may prompt new areas of research to more precisely define this basis and extend these findings to enhance diagnosis and treatment.