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Objective To study the brain functional connectivity(FC)changes in patients with normal tension glau-coma(NTG)and healthy volunteers using FC technique of resting-state functional magnetic resonance imaging(rs-fMRI)based on V1 region seed point(ROI),so as to explore the pathogenesis and early diagnosis of NTG.Methods Fourteen NTG patients(NTG group)who met the inclusion criteria and 14 healthy controls(HCs group)were enrolled.The clinical data of all subjects were collected,and rs-fMRI was performed in both groups.The magnetic resonance data was pre-pro-cessed by software,and bilateral A1 regions were taken as the ROI to analyze their correction with the whole brain voxel time series and obtain the FC value between the ROI and the whole brain by comparison of FC values in resting state be-tween the groups.Pearson correlation analysis was used to explore the relationship between FC value in the brain regions with significant differences with the ROI and clinical variables in the NTG group.Results Compared with the subjects in the HCs group,there were no statistically significant differences in age,gender,body weight,cup-disc ratio and 24 h mean intraocular pressure of patients in the NTG group(all P＞0.05),and there were statistically significant differences in the best corrected visual acuity(BCVA)of both eyes and peripapillary retinal nerve fiber layer thickness(RNFLT)(all P＜0.05).The Pearson correlation analysis showed that FC value of the brain regions with abnormal FC to V1 region were cor-related with RNFLT in the NTG group(P＜0.05).ROI1-left superior frontal gyrus,ROI1-right superior frontal gyrus,ROI2-left cingulate gyrus and ROI2-right middle frontal gyrus were significantly positively correlated with RNFLT(all P＜0.05).Compared with the HCs group,the brain regions with reduced FC to the right ROI in the NTG group were the left superior frontal gyrus and right superior frontal gyrus;the brain regions with reduced FC to the left ROI were the left cingulate gyrus and right middle frontal gyrus.Conclusion Compared to healthy individuals,NTG patients have significant changes in the functional connections between certain specific brain regions and V1 region,including bilateral superior frontal gyrus,left cingulate gyrus,and middle frontal gyrus.The changes in brain functional activity may be caused by visual dysfunction caused by NTG,leading to functional impairment of the visual and cognitive emotion processing brain regions,which may be one of the potential neuropathological mechanisms in NTG patients.
RESUMO
Objective To explore the changes in macular microcirculation status and visual function in patients with normal tension glaucoma(NTG)using the optical coherence tomography angiography(OCTA)and microperimeter MP-3 and analyze the correlation between the two.Methods In this cross-sectional observational study,17 NTG patients(30 eyes)were collected as the NTG group and then divided into mild,moderate and severe NTG subgroups according to the severity of the disease.During the same period,13 healthy subjects(23 eyes)with the same age and gender distribution were selected as the control group.OCTA was used to obtain linear density(LD)and perfusion density(PD)of superficial retinal vessels in the macular area.The microperimeter MP-3 was used to measure retinal sensitivity(RS)within 10° and fixation rate at 2° and 4° of the macular area.The OCTA parameters and microperimeter MP-3 parameters were compared among all groups,and the correlation between OCTA parameters and microperimeter MP-3 parameters in NTG patients was analyzed.Results There were no significant differences in LD and PD between the control group and the mild NTG sub-group in the central and nasal sides of the macula;the LD and PD in the remaining regions and overall average LD and PD showed a gradual downward trend in the control group and the mild,moderate and severe NTG subgroups.Compared with the control group,the RS of the mild NTG subgroup was lower in the inferior and temporal regions of the macular area.The RS of each region and overall average RS in the macular area decreased with the aggravation of the NTG.In the NTG group,LD and PD were significantly positively correlated with RS in each region and overall average RS in the macular area(all P＜0.05).In the NTG group,LD and PD were positively correlated with P2 in some regions of the macular area.Con-clusion Compared with the control group,the macular microcirculation status and visual function of NTG patients signif-icantly decreased with the progression of the disease;there is a significant correlation between macular LD and RS in NTG patients.