Department of Neurology, Penn State College of Medicine, Hershey, PA, USA.
J Neurol Sci. 2012 Nov 15;322(1-2):206-10. doi: 10.1016/j.jns.2012.05.041. Epub 2012 Jun 10.
The cerebral microvasculature cannot be easily studied non-invasively. Because the retina and brain share embryological, anatomical and physiological similarities, studies of retinal blood vessels may prove to be useful as a surrogate marker for cerebrovascular disease. In epidemiological studies abnormal retinal arteriovenous ratios (AVRs) predict the risk of stroke and vascular dementia. However, the association between retinal vasoreactivity, cerebral small vessel ischemic disease, and cerebral blood vessel function remains unknown.
To examine (1) the association between cerebral ischemic white matter disease (WMD) and retinal microvessel behavior and (2) the relationship between retinal blood vessel reactivity and measures of cerebrovascular function.
Cohort study of 12 patients with ischemic WMD and 14 healthy controls. Retinal vasoreactivity was measured following high frequency flicker light stimulation. Middle cerebral artery (MCA) vasoreactivity was measured using transcranial Doppler ultrasound (TCD). Magnetic resonance imaging scans (MRIs) were reviewed for evidence of ischemic WMD.
Patients with ischemic WMD had attenuated retinal venous (2.2% ± 0.27 SD, vs. controls 6% ± 0.7 SD, p=0.002, CI 95%) and arterial (1.9% ± 0.8 SD, vs. controls 4.9% ± 0.8 SD, p=0.004, CI 95%) vasoreactivity compared to controls. An attenuated retinal venous light flicker response was associated with a significant decrease of MCA vasoreactivity (r=0.45, p=0.05, CI 95%). Decreased AVRs, an indicator for altered retinal vessel architecture in patients with cerebral chronic ischemic WMD, were also significantly correlated with dysfunction of cerebral vasoreactivity (r=0.69, p=0.001, CI 95%).
In this study functional and structural impairment of the retinal microvasculature were associated with ischemic WMD and measures of cerebral vascular function. Microvascular dysfunction in the eye may predict cerebral small vessel disease, but validation by larger studies is needed.
脑微血管不易进行非侵入性研究。由于视网膜和大脑具有胚胎学、解剖学和生理学上的相似性，因此对视网膜血管的研究可能有助于成为脑血管疾病的替代标志物。在流行病学研究中，异常的视网膜动静脉比值（AVR）可预测中风和血管性痴呆的风险。然而，视网膜血管反应性与脑小血管缺血性疾病和脑血管功能之间的关系尚不清楚。
检查（1）脑缺血性白质疾病（WMD）与视网膜微血管行为之间的关系，以及（2）视网膜血管反应性与脑血管功能测量之间的关系。
对 12 例缺血性 WMD 患者和 14 例健康对照者进行队列研究。使用高频闪烁光刺激测量视网膜血管反应性。使用经颅多普勒超声（TCD）测量大脑中动脉（MCA）血管反应性。对磁共振成像（MRI）扫描进行回顾性分析，以确定是否存在缺血性 WMD。
与对照组相比，缺血性 WMD 患者的视网膜静脉（2.2%±0.27 SD，vs. 对照组 6%±0.7 SD，p=0.002，95%CI）和动脉（1.9%±0.8 SD，vs. 对照组 4.9%±0.8 SD，p=0.004，95%CI）血管反应性减弱。视网膜静脉光闪烁反应减弱与 MCA 血管反应性显著下降相关（r=0.45，p=0.05，95%CI）。患有慢性脑缺血性 WMD 的患者视网膜血管结构改变的 AVR 降低也与脑血管反应性功能障碍显著相关（r=0.69，p=0.001，95%CI）。
在这项研究中，视网膜微血管的功能和结构损伤与缺血性 WMD 和脑血管功能测量相关。眼部微血管功能障碍可能预示着脑小血管疾病，但需要更大规模的研究来验证。
