Department of Ophthalmology, Loyola University Medical Center, Maywood, Illinois, USA.
Microcirculation. 2012 Aug;19(6):521-9. doi: 10.1111/j.1549-8719.2012.00182.x.
To evaluate the feasibility of conjunctival hemodynamic measurements based on assessment of reproducibility, validity, and response to acute hypotension.
Image sequences of the conjunctival microvasculature of rabbits were captured using a slit lamp biomicroscope under a steady-state condition, after topical administration of phenylephrine, and after intravenous administration of esmolol. Venous hemodynamic parameters (diameter, blood velocity, blood flow, and wall shear stress) were derived.
Conjunctival venous diameters ranged from 9 to 34 μm and blood velocities ranged from 0.08 to 0.95 mm/s. Coefficients of variation of venous diameter and blood velocity measurements were, on average, 6% and 14%, respectively. Automated and manual measurements of venous diameter and velocity were highly correlated (R = 0.97; p < 0.001; n = 16). With phenylephrine administration, diameter and velocity were reduced by 21% and 69%, respectively. Following esmolol administration, blood pressure was reduced with a concomitant decrease in velocity, followed by recovery to baseline. Venous blood velocity, flow, and WSS were correlated with blood pressure (R ≥ 0.52; p ≤ 0.01).
The feasibility of quantifying alterations in microvascular hemodynamics in the bulbar conjunctiva was established. The method is of potential value in evaluating microcirculatory hemodynamics related to cardiovascular function.
评估基于评估重复性、有效性和对急性低血压反应的结膜血流动力学测量的可行性。
使用裂隙灯生物显微镜在稳态条件下、局部给予苯肾上腺素后和静脉给予艾司洛尔后捕获兔结膜微血管的图像序列。得出静脉血流动力学参数（直径、血流速度、血流量和壁面切应力）。
结膜静脉直径范围为 9 至 34μm，血流速度范围为 0.08 至 0.95mm/s。静脉直径和血流速度测量的变异系数平均分别为 6%和 14%。静脉直径和速度的自动和手动测量高度相关（R=0.97；p<0.001；n=16）。给予苯肾上腺素后，直径和速度分别减少了 21%和 69%。给予艾司洛尔后，血压降低，速度随之降低，随后恢复到基线。静脉血流速度、流量和 WSS 与血压相关（R≥0.52；p≤0.01）。
在球结膜中定量评估微血管血液动力学变化的可行性已经确立。该方法在评估与心血管功能相关的微循环血液动力学方面具有潜在价值。
