Levi D M
University of Houston, College of Optometry, TX 77204-6052, USA.
Curr Opin Ophthalmol. 1994 Oct;5(5):3-10.
This article focuses on three important issues that have received much attention during the past year. The first is sensitive periods for amblyopia. Recent physiological studies suggest a surprising degree of neural plasticity in the adult visual cortex. A review of the literature suggests that at least some human amblyopes retain cortical plasticity into adulthood. The second issue is new methods of treatment for amblyopia. Certain neurotransmitters have been implicated in neuronal plasticity. Based on this finding, a potentially promising new method for treating amblyopia, levodopa, is being tested in adults and children with amblyopia. Unfortunately the early results provide more questions than answers. The third topic is neural mechanisms of amblyopia. In primates and humans, the weight of evidence suggests that the neural effects of strabismus and anisometropia are expressed primarily in the cortex. These cortical effects are expressed in a loss of cortical neurons and in alterations in the contrast sensitivity and range of preferred spatial frequencies of the neurons dominated by the amblyopic eye. The relationship between these physiological effects and psychophysical performance is reviewed.
本文聚焦于过去一年中备受关注的三个重要问题。第一个是弱视的敏感期。最近的生理学研究表明，成年视觉皮层中存在惊人程度的神经可塑性。文献综述表明，至少一些人类弱视患者在成年后仍保留皮层可塑性。第二个问题是弱视的新治疗方法。某些神经递质与神经元可塑性有关。基于这一发现，一种潜在有前景的弱视治疗新方法——左旋多巴，正在弱视成人和儿童中进行测试。不幸的是，早期结果带来的问题比答案更多。第三个主题是弱视的神经机制。在灵长类动物和人类中，大量证据表明斜视和屈光参差的神经效应主要表现在皮层。这些皮层效应表现为皮层神经元的丧失，以及弱视眼主导的神经元的对比敏感度和偏好空间频率范围的改变。本文综述了这些生理效应与心理物理学表现之间的关系。
