Huang Yufeng, Feng Lixia, Zhou Yifeng
aDepartment of Electronic Science and Technology, Center of Biomedical Engineering bCAS Key Laboratory of Brain Function and Disease, School of Life Sciences, University of Science and Technology of China cDepartment of Ophthalmology, First Affiliated Hospital, Anhui Medical University, Hefei, Anhui, People's Republic of China.
Neuroreport. 2017 May 3;28(7):397-403. doi: 10.1097/WNR.0000000000000767.
Focal visual stimulation typically results in the activation of a large portion of the early visual cortex. This spread of activity is attributed to long-range lateral interactions. Such long-range interactions may serve to stabilize a visual representation or to simply modulate incoming signals, and any associated dysfunction in long-range activation may reduce sensitivity to visual information in conditions such as amblyopia. We sought to measure the dispersion of cortical activity following local visual stimulation in a group of patients with amblyopia and matched normal. Twenty adult anisometropic amblyopes and 10 normal controls participated in this study. Using a multifocal stimulation, we simultaneously measured cluster sizes to multiple stimulation points in the visual field. We found that the functional MRI (fMRI) response cluster size that corresponded to the fellow eye was significantly larger as opposed to that corresponding to the amblyopic eye and that the fMRI response cluster size at the two more central retinotopic locations correlated with amblyopia acuity deficit. Our results suggest that the amblyopic visual cortex has a diminished long-range communication as evidenced by significantly smaller cluster of activity as measured with fMRI. These results have important implications for models of amblyopia and approaches to treatment.
局部视觉刺激通常会导致早期视觉皮层的大部分区域被激活。这种活动的扩散归因于长程侧向相互作用。这种长程相互作用可能有助于稳定视觉表征或仅仅调节传入信号，并且在诸如弱视等情况下，长程激活中的任何相关功能障碍都可能降低对视觉信息的敏感性。我们试图测量一组弱视患者和匹配的正常受试者在局部视觉刺激后皮层活动的扩散情况。20名成年屈光参差性弱视患者和10名正常对照参与了这项研究。使用多焦点刺激，我们同时测量了视野中多个刺激点的簇大小。我们发现，与弱视眼对应的功能磁共振成像（fMRI）反应簇大小相比，与对侧眼对应的反应簇大小明显更大，并且在两个更中央的视网膜定位位置的fMRI反应簇大小与弱视视力缺陷相关。我们的结果表明，弱视视觉皮层的长程通信减少，这通过fMRI测量的明显更小的活动簇得以证明。这些结果对弱视模型和治疗方法具有重要意义。
