阿尔茨海默病患者视网膜结构及功能的改变

Changes in retinal structure and function of Alzheimer's patients

阿尔茨海默病(Alzheimer's disease,AD)是一种神经退行性疾病,会出现记忆力下降、认知功能障碍、行为异常等表现。其特征性病理表现为Aβ蛋白沉积和神经纤维缠结,从而引起大脑的神经元细胞数量减少。视网膜作为中枢神经系统的外延,与中枢神经系统有着相似的组织解剖结构,Aβ斑在其中也有表达。并且,在对AD患者的眼科检查中发现,患者的视网膜出现神经节细胞数量减少、神经纤维层厚度变薄、黄斑容积变小及视网膜血管密度减少等异常变化,进而表现为视野缺损、对比敏感度下降等症状,出现了神经退行性改变。而且研究发现,视网膜的神经退行性病变早于大脑老年斑的形成。此外,研究发现,姜黄素是一种天然安全的荧光染料,可以标记视网膜Aβ斑。以上提示了视网膜有望成为AD的早期诊断窗口。

Alzheimer＇s disease（AD）, a neurodegenerative disease, can result in memory loss,cognitive and behavioral deficits. The pathological hallmarkes are β amyloid plaques and neurofibrillary tangles which lead loss of neurons in brain. As the extension of the central nervous system, retina has a similar tissue anatomy with central nervous system. The β amyloid plaques have also been detected in retina of AD. Furthermore, according to eye examinations of AD patients, we have found the loss of retinal ganglion cells, the attenuation of retinal nerve fiber layer thickness, the smaller changes of macula lutea, the decline of vascular density and so on. And then, there occurs the visual field loss and the decline of contrast sensitivity and so on in AD patients. Thus, the retina has occurred nerve degenerative changes in AD. Meanwhile, there has been proved that the retina nerve degeneration is even earlier than senile plaques formation in brain. In addition,curcumin, a natural and safe fluorescent dye, can be used to label β amyloid plaques in retina. The above suggests that retina can be a window for the early diagnosis of AD.