Lee K M, Lee S H, Kim N Y, Kim C Y, Sohn J W, Choi M Y, Gyu Choi D, Hwang J M, Ho Park K, Lee D S, Suk Yu Y, Hyun Chang K
Department of Neurology, Seoul National University, 110-744, Seoul, South Korea.
Neurosci Res. 2001 Jun;40(2):147-53. doi: 10.1016/s0168-0102(01)00220-6.
Strabismus and anisometropia early in life frequently causes monocular amblyopia. Activation of the visual cortex is compared between the two types of amblyopia to elucidate differences in the pathogenetic mechanism of the disease.
Using an EPI gradient echo sequence in 1.5T MRI, calcarine activation by monocular viewing of checkerboard patterns with reversal was examined in terms of binocularity of the activation and dependence on the spatial frequency of the stimuli.
First, the proportion of voxels activated by both normal and amblyopic eye monocular stimulations is lower in the strabismic group than in the anisometropic group. Second, the activation by higher-spatial-frequency stimuli is reduced in the anisometropic group, but not in the strabismic group.
These findings from the human visual cortex are consistent with the view proposed based on animal research that the loss of binocular interaction and the undersampling of high-spatial-frequency components of visual stimuli are each one of the underlying changes in strabismic and anisometropic amblyopia, respectively.
生命早期的斜视和屈光参差常导致单眼弱视。比较两种类型弱视中视觉皮层的激活情况，以阐明该疾病发病机制的差异。
在1.5T磁共振成像中使用回波平面成像梯度回波序列，通过单眼观察带有反转的棋盘格图案来检查距状裂的激活情况，包括激活的双眼性以及对刺激空间频率的依赖性。
首先，斜视组中正常眼和弱视眼单眼刺激激活的体素比例低于屈光参差组。其次，屈光参差组中高空间频率刺激的激活减少，但斜视组未减少。
来自人类视觉皮层的这些发现与基于动物研究提出的观点一致，即双眼相互作用的丧失和视觉刺激高空间频率成分的欠采样分别是斜视性弱视和屈光参差性弱视的潜在变化之一。
