Department of Neurology, the First Affiliated Hospital of Anhui Medical University, Hefei, China.
Anhui Province Key Laboratory of Cognition and Neuropsychiatric Disorders, Hefei, China.
J Alzheimers Dis. 2021;79(3):1307-1316. doi: 10.3233/JAD-200971.
There is increasing evidence that Alzheimer's disease (AD) patients may present decreased cerebral blood perfusion before pathological brain changes. Using the retina as a window to the brain, we can study disorders of the central nervous system through the eyes.
This study aimed to investigate differences in retinal structure and vessel density (VD) between patients with mild AD and healthy controls (HCs). Furthermore, we explored the relationship between retinal VD and cognitive function.
We enrolled 37 patients with AD and 29 age-matched HCs who underwent standard ophthalmic optical coherence tomography angiography (OCTA) for evaluation of the retinal layer thickness and VD parameters. Cognitive function was evaluated using a battery of neuropsychological assessments. Finally, the correlations among retinal layer thickness, VD parameters, and cognitive function were evaluated.
The retinal fiber layer thickness and retinal VD of patients with AD were significantly reduced compared with HCs. The retinal VD was significantly correlated with overall cognition, memory, executive, and visual-spatial perception functions. However, there was no significant between-group difference in the macular thickness.
Our findings indicate a positive correlation between retinal VD and some, but not all, cognitive function domains. Most importantly, we demonstrated the role of OCTA in detecting early capillary changes, which could be a noninvasive biomarker for early AD.
越来越多的证据表明，阿尔茨海默病（AD）患者在出现病理性脑改变之前可能会出现脑血流灌注减少。通过将视网膜作为观察大脑的窗口，我们可以通过眼睛研究中枢神经系统疾病。
本研究旨在探讨轻度 AD 患者与健康对照组（HCs）之间视网膜结构和血管密度（VD）的差异。此外，我们还探讨了视网膜 VD 与认知功能之间的关系。
我们招募了 37 名 AD 患者和 29 名年龄匹配的 HCs，他们接受了标准的眼科光相干断层扫描血管造影（OCTA）评估视网膜层厚度和 VD 参数。使用一系列神经心理学评估来评估认知功能。最后，评估了视网膜层厚度、VD 参数和认知功能之间的相关性。
AD 患者的视网膜神经纤维层厚度和视网膜 VD 明显低于 HCs。视网膜 VD 与整体认知、记忆、执行和视觉空间感知功能显著相关。然而，黄斑厚度在两组之间没有显著差异。
我们的发现表明视网膜 VD 与一些但不是所有认知功能领域之间存在正相关。最重要的是，我们证明了 OCTA 在检测早期毛细血管变化中的作用，这可能是早期 AD 的一种非侵入性生物标志物。
