Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
J Neurol Neurosurg Psychiatry. 2012 Sep;83(9):917-22. doi: 10.1136/jnnp-2011-301628. Epub 2012 Jun 25.
Alzheimer's disease (AD) is the most common cause of dementia. Furthermore, over the last few decades, there has been a shift towards identifying earlier stages of AD, which include mild cognitive impairment (MCI). Improved methods of screening and early detection are essential to identify cognitively normal individuals who have a high risk of developing MCI and AD, so that interventions can be developed to delay the progression of specific disease-related pathologies. Thus far, novel biomarkers that have been examined include structural and functional neuroimaging as well as biochemical analysis of cerebrospinal fluid. However, in spite of these efforts, there is still an urgent need for unravelling additional novel biomarkers for AD and MCI. As the retina shares many features with the brain, including embryological origin, anatomical (such as microvascular bed) and physiological characteristics (such as blood-tissue barrier), it has been suggested that the retina may provide an easily accessible and non-invasive way of examining pathology in the brain. While most AD-related pathology occurs in the brain, the disease has also been reported to affect different regions of the retina, including the macular region and optic disc. Studies have suggested that retinal pathology, such as deposits in the macular region, decreased retinal nerve fibre thickness, and optic disc cupping and retinal microvascular abnormalities may be related to AD and cognitive impairment. This article presents a review of current literature on retinal involvement in AD and MCI.
阿尔茨海默病（AD）是痴呆症最常见的病因。此外，在过去几十年中，人们已经转向识别 AD 的早期阶段，包括轻度认知障碍（MCI）。改进的筛选和早期检测方法对于识别认知正常但有发生 MCI 和 AD 高风险的个体至关重要，以便可以开发干预措施来延缓特定疾病相关病理学的进展。到目前为止，已经检查了包括结构和功能神经影像学以及脑脊液生化分析在内的新型生物标志物。然而，尽管进行了这些努力，但仍然迫切需要发现 AD 和 MCI 的其他新型生物标志物。由于视网膜与大脑具有许多共同特征，包括胚胎起源、解剖学（如微血管床）和生理学特征（如血液-组织屏障），因此有人认为视网膜可能提供一种易于接近和非侵入性的方法来检查大脑中的病理学。虽然大多数与 AD 相关的病理学发生在大脑中，但也有报道称该疾病还会影响视网膜的不同区域，包括黄斑区和视盘。研究表明，视网膜病理学，如黄斑区的沉积物、视网膜神经纤维厚度减少以及视盘凹陷和视网膜微血管异常，可能与 AD 和认知障碍有关。本文综述了目前关于 AD 和 MCI 中视网膜受累的文献。
