Cognitive impairment and dementia are major medical, social, and economic public health issues worldwide with significant implications for life quality in older adults. The leading causes are Alzheimer’s disease (AD) and vascular cognitive impairment/dementia (VCID). In both conditions, pathological alterations of the cerebral microcirculation play a critical pathogenic role. Currently, the main pathological biomarkers of AD—β-amyloid peptide and hyperphosphorylated tau proteins—are detected either through cerebrospinal fluid (CSF) or PET examination. Nevertheless, given that they are invasive and expensive procedures, their availability is limited. Being part of the central nervous system, the retina offers a unique and easy method to study both neurodegenerative disorders and cerebral small vessel diseases in vivo. Over the past few decades, a number of novel approaches in retinal imaging have been developed that may allow physicians and researchers to gain insights into the genesis and progression of cerebromicrovascular pathologies. Optical coherence tomography (OCT), OCT angiography, fundus photography, and dynamic vessel analyzer (DVA) are new imaging methods providing quantitative assessment of retinal structural and vascular indicators—such as thickness of the inner retinal layers, retinal vessel density, foveal avascular zone area, tortuosity and fractal dimension of retinal vessels, and microvascular dysfunction—for cognitive impairment and dementia. Should further studies need to be conducted, these retinal alterations may prove to be useful biomarkers for screening and monitoring dementia progression in clinical routine. In this review, we seek to highlight recent findings and current knowledge regarding the application of retinal biomarkers in dementia assessment.

认知障碍和痴呆是世界范围内主要的医疗、社会和经济公共卫生问题，对老年人的生活质量具有重大影响。主要原因是阿尔茨海默病 (AD) 和血管性认知障碍/痴呆 (VCID)。在这两种情况下，脑微循环的病理改变都起着关键的致病作用。目前，AD的主要病理生物标志物——β-淀粉样肽和过度磷酸化的tau蛋白——通过脑脊液（CSF）或PET检查来检测。然而，鉴于它们是侵入性且昂贵的手术，其可用性是有限的。作为中枢神经系统的一部分，视网膜提供了一种独特且简单的方法来研究体内神经退行性疾病和脑小血管疾病。在过去的几十年里，已经开发了许多视网膜成像的新方法，这些方法可以让医生和研究人员深入了解脑微血管病理的发生和进展。光学相干断层扫描 (OCT)、OCT 血管造影、眼底摄影和动态血管分析仪 (DVA) 是新的成像方法，可定量评估视网膜结构和血管指标，例如视网膜内层厚度、视网膜血管密度、黄斑中心凹无血管区视网膜血管的面积、扭曲度和分形维数以及微血管功能障碍——用于认知障碍和痴呆。如果需要进行进一步的研究，这些视网膜改变可能被证明是在临床常规中筛查和监测痴呆进展的有用生物标志物。 在这篇综述中，我们试图强调有关视网膜生物标志物在痴呆评估中应用的最新发现和当前知识。