弱视与视觉系统可塑性

Amblyopia and the plasticity in visual system

弱视是一种发育性眼科疾病，其发病与视觉系统发育关键期内的异常视觉经验密切相关。传统的弱视治疗方法对已超过视觉发育关键期的大龄儿童和成年弱视患者几乎没有效果。知觉学习指经过感知觉训练引起的知觉任务成绩的特异性提高，其生理学基础是神经系统的可塑性。近年来的研究表明，视知觉学习可以显著提高正常人以及诸多高等动物的视知觉功能，并且可以显著改善弱视等视觉系统功能受损患者的视觉功能。动物电生理学研究表明视知觉学习导致了视皮层内神经元调谐特性的改善。这些研究提示我们，即使超过了视觉系统发育的关键期，视觉神经系统仍然存在一定的可塑性。

Amblyopia is an ophthalmic diseases, usually derives from functional imbalance between two eyes during early development. Its treatment depends on the plasticity of the visual system. Once beyond the critical period, like older children with amblyopia and adult amblyopia, the treatment effect of traditional methods is powerless. Perceptual learning refers to a selectively improved performance of perceptual tasks after perceptual training, which physiological mechanism is the plasticity of the neural system. Recently, visual perceptual learning has been shown to significantly improve visual functions of human and animals. Additionally, perceptual learning could also improve impaired visual functions of amblyopia and other patients with visual dysfunction. Animal electrophysiological studies showed that perceptual learning resulted in an improvement of neuronal tuning properties. All these findings suggested that neural plasticity maintained in some degree even beyond the critical period of visual development.