Department of Neurobiology, Weizmann Institute of Science, 234 Herzl Street, Rehovot 76100, Israel.
Nat Rev Neurol. 2013 Jan;9(1):44-53. doi: 10.1038/nrneurol.2012.227. Epub 2012 Nov 20.
Philosophers defined the eye as a window to the soul long before scientists addressed this cliché to determine its scientific basis and clinical relevance. Anatomically and developmentally, the retina is known as an extension of the CNS; it consists of retinal ganglion cells, the axons of which form the optic nerve, whose fibres are, in effect, CNS axons. The eye has unique physical structures and a local array of surface molecules and cytokines, and is host to specialized immune responses similar to those in the brain and spinal cord. Several well-defined neurodegenerative conditions that affect the brain and spinal cord have manifestations in the eye, and ocular symptoms often precede conventional diagnosis of such CNS disorders. Furthermore, various eye-specific pathologies share characteristics of other CNS pathologies. In this Review, we summarize data that support examination of the eye as a noninvasive approach to the diagnosis of select CNS diseases, and the use of the eye as a valuable model to study the CNS. Translation of eye research to CNS disease, and deciphering the role of immune cells in these two systems, could improve our understanding and, potentially, the treatment of neurodegenerative disorders.
哲学家们早在科学家们提出这个陈词滥调以确定其科学依据和临床相关性之前，就将眼睛定义为通往灵魂的窗户。从解剖学和发育学的角度来看，视网膜是中枢神经系统的延伸；它由视网膜神经节细胞组成，其轴突形成视神经，其纤维实际上是中枢神经系统的轴突。眼睛具有独特的物理结构和局部表面分子和细胞因子阵列，并且存在类似于大脑和脊髓中的特异性免疫反应。几种影响大脑和脊髓的明确的神经退行性疾病在眼睛中有表现，并且眼部症状通常先于此类中枢神经系统疾病的常规诊断。此外，各种特定于眼睛的病理学与其他中枢神经系统病理学具有共同的特征。在这篇综述中，我们总结了支持将眼睛检查作为诊断特定中枢神经系统疾病的非侵入性方法的证据，以及将眼睛作为研究中枢神经系统的有价值模型的证据。将眼部研究转化为中枢神经系统疾病，并破译这两个系统中免疫细胞的作用，可能会增进我们对神经退行性疾病的理解，并可能改善其治疗方法。
