弱视视觉运动功能的功能磁共振研究  

Study of the perception of visual motion in amblyopia using functional MRI

作　　者：卢光明[1] 张志强[1] 梁平[2] 周文珍[1] 郑玲[1] 尹婕[1] 

机构地区：[1]南京军区南京总医院医学影像科,210029 [2]江苏省人民医院眼科

出　　处：《中华放射学杂志》2006年第5期494-497,共4页Chinese Journal of Radiology

摘　　要：目的采用功能磁共振成像(fMR I)技术分别对屈光不正及斜视性弱视在视觉运动刺激时的皮层反应进行观察,探索不同弱视的视觉运动受影响机制。方法采用旋转光栅/静止光栅为视觉运动刺激源,在1.5 T的磁共振仪下分别对7例临床诊断为屈光不正型弱视及10例斜视型的弱视患者在单眼刺激下行功能磁共振检查,SPM(statistical param etric m app ing)软件进行数据处理,结果采用单样本数据分析。并设定双眼间反应体素差异水平指数,采用Mann-Whitney秩和检验,用以判断双眼分别刺激时皮层反应的差异水平。结果两组样本中,双侧枕叶视觉运动功能区域有不同程度的反应,弱视眼刺激较正常眼有额外的额叶反应。以中颞(MT)区为感兴趣区进行分析,7例屈光不正型弱视患者中,弱视眼反应水平相比正常眼均下降,10例斜视性弱视,除1例无任何反应外,5例弱视眼反应水平较正常眼下降,4例较正常增高。两组数据体素差异水平指数(IAD)之间有统计学差异(Z=2.382,P=0.017)。结论单眼视觉运动刺激时,弱视眼比正常眼有更多的脑区参与反应。屈光不正型弱视皮层可能存在视觉运动功能的下降,斜视性弱视功能受损情况可能与弱视的程度有关;提示两种弱视的视觉运动功能受损情况不一致。Objective To research the pathophysiological mechanism of anisometropic and strabismic amblyopia through observation of the cortex activation under the stimulus of visual motion using functional MRI （fMRI） . Methods Seven patients with anisometropic amblyopia and 10 patients with strabismic amblyopia were examined under the stimulus with the paradigm that task and control states were rotating and stationary grating with 1.5 T MR scanners. The data were processed using software of SPM offline, and the result was analyzed with single subject. An index of interocular difference of activation （IDA） was set for Mann-Whitney rank sum test to denote the extension of difference between activation of each eye. Results There appeared activation on bilaterally occipital lobe in both group of amblyopia patients. There was mild activation on frontal lobe when amblyopic eyes were stimulated, but no activation when sound eyes. The MT area was regarded as region of interesting when analyzed, the activation of all sound eyes was stronger than amblyopic eyes in 7 anisometropic amblyopia patients. There were 5 patients whose level of activation of amblyopic eye＇s were lower than sound eye , and four were higher than sound eye, among the strabismic amblyopia patients except one patient＇s activation was none. There was statistical difference between IDA value of two groups （ Z = 2. 382, P = 0. 017 ）. Conclusion There are more cortex areas activated of amblyopic eye than sound eye when single eye is stimulated. The function of visual motion maybe has been affected in anisometropic amblyopia. In strabismic amblyopia, the function of visual motion may relate to the underlying mechanism of strabismic, which suggests, which suggests, as for the impairment of perception of visual motion, there is difference between two types of amblyopia.

关 键 词：弱视 磁共振成像 

分 类 号：R445.2[医药卫生—影像医学与核医学]