Optical Coherence Tomography (OCT): Imaging the Visual Pathway as a Model for Neurodegeneration
Optical Coherence Tomography (OCT): Imaging the Visual Pathway as a Model for Neurodegeneration
复制标题
DOI：
10.1007/s13311-010-0005-1
复制
发表时间：
2011-01-01
影响因子：
5.7
通讯作者：
Balcer, Laura J.
中科院分区：
文献类型：
--
作者：
Galetta, Kristin M.;Calabresi, Peter A.;Balcer, Laura J.
轴突和神经元变性是多发性硬化症(MS)和其他影响前视觉通路的神经疾病的重要特征。光学相干断层扫描(OCT)是一种非侵入性技术，可以对视网膜神经纤维层(RNFL)进行成像，RNFL是一个主要由形成视神经、交叉和视束的神经节细胞轴突组成的结构。由于视网膜轴突在穿过筛板之前是无髓鞘的，RNFL是一个理想的结构(没有其他中枢神经系统束有这种独特的排列)，可以可视化神经退化、神经保护甚至神经修复的过程。OCT能够以快速和可重复的方式提供高分辨率的视网膜解剖重建，并允许对RNFL(轴突)以及黄斑中的神经节细胞和其他神经元进行客观分析。在对多发性硬化症(MS)患者进行的系统OCT检查中，与无疾病对照相比，RNFL厚度和黄斑体积都减少了。值得注意的是，这些标志着视网膜结构紊乱的变化，即使在没有急性脱髓鞘视神经炎病史的情况下，也会随着时间的推移而发生。在MS中，RNFL轴突丢失最严重的是那些低对比度字母敏锐度相应降低的眼睛(一种敏感的视力测试，涉及在白色背景上感知灰色字母)，以及那些根据经过验证的磁共振成像技术衡量的大脑萎缩程度最大的患者。这些独特的结构-功能相关性使前视觉通路成为研究针对轴突和神经元变性的标准和新疗法的效果的理想模型。我们概述了OCT的物理原理，它作为一种非侵入性成像技术的独特特性，以及它在理解MS脑组织损伤机制、其他视神经疾病和神经疾病方面的潜在应用。
Axonal and neuronal degeneration are important features of multiple sclerosis (MS) and other neurologic disorders that affect the anterior visual pathway. Optical coherence tomography (OCT) is a non-invasive technique that allows imaging of the retinal nerve fiber layer (RNFL), a structure which is principally composed of ganglion cell axons that form the optic nerves, chiasm, and optic tracts. Since retinal axons are nonmyelinated until they penetrate the lamina cribrosa, the RNFL is an ideal structure (no other central nervous system tract has this unique arrangement) for visualizing the processes of neurodegeneration, neuroprotection and, potentially, even neuro-repair. OCT is capable of providing high-resolution reconstructions of retinal anatomy in a rapid and reproducible fashion and permits objective analysis of the RNFL (axons) as well as ganglion cells and other neurons in the macula. In a systematic OCT examination of multiple sclerosis (MS) patients, RNFL thickness and macular volumes are reduced when compared to disease-free controls. Conspicuously, these changes, which signify disorganization of retinal structural architecture, occur over time even in the absence of a history of acute demyelinating optic neuritis. RNFL axonal loss in MS is most severe in those eyes with a corresponding reduction in low-contrast letter acuity (a sensitive vision test involving the perception of gray letters on a white background) and in those patients who exhibit the greatest magnitude of brain atrophy, as measured by validated magnetic resonance imaging techniques. These unique structure-function correlations make the anterior visual pathway an ideal model for investigating the effects of standard and novel therapies that target axonal and neuronal degeneration. We provide an overview of the physics of OCT, its unique properties as a non-invasive imaging technique, and its potential applications toward understanding mechanisms of brain tissue injury in MS, other optic neuropathies, and neurologic disorders.