屈光不正型弱视的功能磁共振成像研究

Study of pathology of anisometropic amblypia using functional MRI

目的 :采用功能磁共振成像技术对弱视的视觉运动功能进行研究。 方法 :采用组块设计方式 ,5例单眼屈光不正型弱视患者与 8例健康志愿者分别进行两侧单眼的旋转光栅刺激 ,1 .5T磁共振扫描 ,SPM软件离线处理。分别比较弱视样本两单眼间及两组样本间不同的反应水平。 结果 :弱视患者弱视眼的反应体素数目及反应强度均较正常眼低 (tAN=3.2 8,P <0 .0 5 ;tAT=3.77,P <0 .0 5 ) ;正常人双眼间统计学上无显著性差异 (tNN=1 .2 8,P >0 .1 ;tNT=- 0 .0 2 ,P >0 .5 ) ;比较两眼间反应水平差 (IDA) ,弱视组 (0 .6 93± 0 .2 5 8)较正常组 (0 .1 4 3± 0 .35 7)大。结论 :屈光不正型弱视对视觉运动刺激反应下降 。

Objective: To investigate the anisometropic amblyopia pathology about the visual motion using functional MRI. Methods: Five patients with unilateral anisometropic amblyopia and 8 healthy volunteers were employed in test with epoch fMRI paradigm, viewed the stimuli of rotating grating monocularly with each eye. Data acquisition was performed in 1.5 Tesla MRI scanner, processed by SPM software offline, Comparisons were made between the number of activated voxel of eyes in case and among cases using t test. Results: The activation level (voxel number and T value of activation) of amblyopia eye(AE) was lower than sound eye(SE) in anisometropic amblyopia patients( t AN =3.28, P <0.05; t AT =3.77, P <0.05). There was no statistical interocular difference in normal cases( t NN =1.28, P > 0.1; t NT =-0.02, P >0.5). The interocular difference of activation (IDA) value of amblyopia cases(0.693±0.258) was bigger than healthy cases(0.143±0.357). Conclusion: The activation of visual motion of anisometropic amblyopia eye decreases, which suggests there is functional deficits in visual motion area of extra striate cortex.