摘要目的 评价原发性开角型青光眼(POAG)患者视觉皮层的激活情况,探讨视觉皮层激活与临床检查结果——视网膜神经纤维层(RNFL)厚度和杯盘比(C/D)是否存在相关性.方法 收集25例POAG患者和25名性别、年龄匹配的健康志愿者,对被试者的左、右眼分别进行单眼刺激组块设计的功能MRI (fMRI)试验,视觉刺激采用全屏幕黑白翻转棋盘格,运用3.0TMR采集BOLD-fMRI功能序列和BRAVO结构像序列.数据处理与分析由统计参数映射(SPM5)完成,获得病变组和对照组的组内平均激活图和组间差异图,记录激活区的体素数目、激活强度和MNI坐标.用Xjviewer软件记录病变组个体的激活体素数目,并将之与RNFL值、C/D值及临床分期进行Pearson相关分析,采用两样本t检验方法分析病变组和对照组的RNFL和C/D差异是否有统计学意义.结果 病变组和对照组的组内平均激活图显示双侧枕叶明显激活；组间差异图提示病变组双侧枕叶、左侧海马及左侧小脑半球的激活强度弱于对照组；病变组RNFL均值为(71.56±21.54)μm,对照组为(111.88±9.96) μm,病变组C/D均值为0.71 ±0.18,对照组为0.36 ±0.08,差异均有统计学意义(t值分别为-10.901和11.643,P＜0.05)；病变组枕叶激活体素数目与RNFL、C/D及临床分期无相关性(r值分别为0.157、-0.113和-0.242,P＞0.05).结论 fMRI能显示POAG患者和健康志愿者接受视觉刺激时视觉皮层激活的差异,可作为临床诊断青光眼的补充检查手段.但fMRI的结果分析与RNFL和C/D差异无统计学意义,因此fMRI不能取代疾病严重性评估的临床检查.

abstractsObjective To evaluate the activation of the visual cortex in patients with primary openangle glaucoma (POAG) and to explore whether the neuronal activity corresponds with retinal nerve fiber layer (RNFL) and cup-to-disc (C/D) values.Methods Twenty-five patients and 25 gender-and agematched healthy volunteers were studied.Blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) and three-dimensional brain volume imaging (3 D BRAVO) sequences were obtained using 3 T MR imaging system.A full-screen black-white shift checkerboard was used for visual stimulus during the fMRI experiment and was performed on each eye of all subjects using a visual-acoustical system.All acquired data were postprocessed and analyzed by statistical parametric mapping (SPM).After analysis,individual activated mapping,intra-group mean activated mapping,and inter-group variant mapping were observed.The voxel number,intensity,and Montreal Neurological Institute (MNI) coordinate of the activated clusters were recorded.The Xjviewer software was utilized to obtain activated voxel numbers in occipital lobe.A Pearson correlated test was performed to test the correlation between the number of activated voxels and RNFL,C/D and Hodapp-Anderson-Parrish (HAP) clinical stage.Results Intra-group mean activated mappings of both patients and volunteers showed obvious activation in bilateral occipital lobes.As compared with healthy volunteers,the POAG patients exhibited statistically significantly decreased activation in bilateral occipital lobes,left hippocampus,and left cerebellum,along with lower mean RNFL [(71.56 ±21.54) i m versus (111.88 ± 9.96) μm] and higher C/D values (0.71 ± 0.18 versus 0.36 ± 0.08 ; t value was respectively-10.901 and 11.643,P ＜ 0.05).The number of activated voxels in the occipital lobes of POAG patients did not correlate with RNFL,C/D and HAP clinical stage of the corresponding eye (r value was respectively 0.157,-0.113 and-0.242,P ＞ 0.05).Conclusions fMRI demonstrated differences in visual cortex activation in POAG patients relative to healthy volunteers,suggesting it might be a promising complementary method for diagnosing glaucoma.However,fMRI findings did not correlate with POAG extent,as measured by RNFL and C/D values.Ophthalmological examination remains to play an important role in the evaluation of open-angle glaucoma.