Blum M, Bachmann K, Wintzer D, Riemer T, Vilser W, Strobel J
Department of Ophthalmology, Friedrich Schiller University Jena, Germany.
Graefes Arch Clin Exp Ophthalmol. 1999 Apr;237(4):296-300. doi: 10.1007/s004170050236.
The Bayliss effect describes the reaction of smooth muscle cells in the arterial wall to changes in blood pressure. A rise in mean arterial blood pressure (MAP) causes an autoregulatory myogenic vessel constriction by smooth muscle cells in the arterial wall. The responsiveness of retinal vessels to changes in MAP were analyzed using the Retinal Vessel Analyzer (RVA).
Continuous measurement of retinal arterial vessels was performed in 40 healthy volunteers (age 18-56 years.) over a 9-min period. After a 3-min baseline measurement (phase I), isometric exercise caused a rise in MAP over the next 3 min (phase II). During the last 3 min (phase III) recovery was observed. Blood pressure and ECG were documented simultaneously throughout the experiment.
Exercise caused a significant rise of 22.8 (+/-6.0) mm Hg in MAP (phase II vs. phase I: P<0.001). Retinal arterioles showed 5.5% (+/-2.8%) vasoconstriction (P<0.001). During phase III vessel diameters returned to normal, with no difference from phase I (P = 0.179).
Noninvasive measurement and quantitative analysis of the Bayliss effect in human retinal vessels by means of the RVA is possible. Analysis of retinal arterial autoregulation may provide valuable insight into pathologic conditions such as diabetic or hypertensive retinopathy.
贝利斯效应描述了动脉壁平滑肌细胞对血压变化的反应。平均动脉血压（MAP）升高会导致动脉壁平滑肌细胞发生自动调节性肌源性血管收缩。使用视网膜血管分析仪（RVA）分析视网膜血管对MAP变化的反应性。
对40名健康志愿者（年龄18 - 56岁）的视网膜动脉血管进行9分钟的连续测量。在3分钟的基线测量（第一阶段）后，等长运动在接下来的3分钟内导致MAP升高（第二阶段）。在最后3分钟（第三阶段）观察恢复情况。在整个实验过程中同时记录血压和心电图。
运动导致MAP显著升高22.8（±6.0）mmHg（第二阶段与第一阶段相比：P<0.001）。视网膜小动脉显示出5.5%（±2.8%）的血管收缩（P<0.001）。在第三阶段，血管直径恢复正常，与第一阶段无差异（P = 0.179）。
通过RVA对人视网膜血管中的贝利斯效应进行无创测量和定量分析是可行的。视网膜动脉自动调节的分析可能为糖尿病或高血压性视网膜病变等病理状况提供有价值的见解。
