title: Altered amplitude of low-frequency fluctuation in primary open-angle glaucoma: a resting-state FMRI study.
abstract: OBJECTIVE
  To analyze the altered amplitude of low-frequency fluctuation (ALFF) of the brain using resting-state functional magnetic resonance imaging (fMRI) in patients with primary open-angle glaucoma (POAG).
  
  
  METHODS
  Resting-state fMRI was conducted in 21 POAG patients and 22 age-matched healthy control subjects. After the ALFF and fractional amplitude of low-frequency fluctuation (fALFF) for slow 4 and slow 5 bands were calculated, the results between POAG patients and healthy controls were compared. Then the correlations between ALFF/fALFF values and the disease stage of POAG were analyzed.
  
  
  RESULTS
  Compared with controls, POAG patients showed significantly decreased ALFF/fALFF values in the visual cortices, posterior regions of the default-mode network (DMN), and motor and sensory cortices. Meanwhile, ALFF/fALFF values in the prefrontal cortex, left superior temporal gyrus (STG), right middle cingulate cortex (MCC), and left inferior parietal lobule (IPL) significantly increased in POAG patients. Hodapp-Anderson-Parrish (HAP) score for POAG was positively correlated with ALFF values of the right superior frontal gyrus (SFG) and negatively correlated with that of the left cuneus. For the slow 5 band, the fALFF values of the bilateral middle temporal gyri (MTG) of POAG patients were negatively correlated with HAP score.
  
  
  CONCLUSIONS
  Primary open-angle glaucoma is a neurodegenerative disease involving multiple brain regions, including the visual cortices, DMN, limbic system, and motor and sensory networks. Moreover, the alterations in some of these networks are correlated with the progression of POAG; for the abnormal spontaneous neural activities in the left cuneus, bilateral MTG and right prefrontal cortex are correlated with glaucoma severity.
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Li
authors.affiliation: Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Jianhong
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Mechanical, Electrical and Information Engineering, Shangdong University, Weihai, Shangdong, China.
authors.forename: Zhenchao
authors.initials: Z
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology, Eye Hospital of China Academy of Chinese Medical Sciences, Beijing, China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Xie
authors.affiliation: Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Diya
authors.initials: D
authors.lastname: Yang
authors.affiliation: Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Ningli
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing, China School of Life Science and Technology, Xidian University, Xi'an, Shanxi, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Tian
authors.affiliation: Department of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors.forename: Junfang
authors.initials: J
authors.lastname: Xian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012146:Rest; D014793:Visual Cortex / Q000473:pathology / Q000503:physiopathology*; D055815:Young Adult
keywords: functional magnetic resonance imaging (fMRI); primary open angle glaucoma; resting state fMRI; spontaneous activity