儿童屈光参差性弱视的fMRI研究

目的利用血氧水平依赖性功能性磁共振成像（BOLD—fMRI）技术研究儿童屈光参差性弱视大脑视觉皮层功能受到的影响。资料与方法以1．5T磁共振成像系统采集8例儿童屈光参差性弱视的枕叶视皮层兴趣区BOLD-fMRI数据，比较其弱视眼与健眼，及弱视眼屈光矫正前后皮层激活强度及范围的不同，分析其改变特点及机制。结果弱视眼皮层神经元的反应水平及激活范围在Brodmann 17、18、19区均明显小于对侧眼，并且这种差别在Brodmann 18、19区更加明显。弱视眼矫正屈光不正后皮层活动水平明显增高，激活范围明显增大。结论屈光参差性弱视各级视觉皮层均发生了明显的功能损害，高级别纹外皮层可能比低级别纹状皮层损害更加明显；弱视眼矫正屈光不正可部分提高皮层活动能力及活动范围，屈光参差性弱视患者应尽早手术或配镜矫正。

fMRI Study in Anisometropic Amblyopia for Children

Objective To assess the influence of anisometropic amblyopia on different level of visual cortex with Bold fMRI.Materials and Methods The amblyopia eyes and the contralateral normal eyes before and after correcting the diopter on 8 children with anisometropic amblyopias using 1.5T MRI were studied respectively.The activations on different levels of visual cortexes were observed.Results The activation by amblyopic eyes was found to be significantly less than that by the contralateral sound eyes on brodmann 17,18,19 area.The activation was significantly increased of amblyopic eyes when their diopter was corrected.However there was still distinct difference between two eyes in different levels of visual cortex.Conclusion There are remarkable defects on different levels of visual cortex in anisometropic amblyopia.Extrastriate cortex has more activated defects than the striate cortex.Correcting diopter can increase amblyopic eye's cortex activation distinctly,which indicates anisometropic amblyopias should be corrected it as early as possible.