Strenn K, Menapace R, Rainer G, Findl O, Wolzt M, Schmetterer L
Department of Ophthalmology B, University of Vienna, Austria.
Br J Ophthalmol. 1997 May;81(5):360-4. doi: 10.1136/bjo.81.5.360.
AIMS/BACKGROUND: Recently a commercially available scanning laser Doppler flowmeter has been produced, which provides two dimensional maps of the retinal perfusion. The aim of the present study was to investigate the reproducibility and the sensitivity of these measurements.
16 healthy subjects were randomised to inhale different gas mixtures of oxygen and nitrogen in a double blind crossover study. The following gas mixtures of oxygen and nitrogen were administered: 100% oxygen + 0% nitrogen, 80% oxygen + 20% nitrogen, 60% oxygen + 40% nitrogen, 40% oxygen + 60% nitrogen, 30% oxygen + 70% nitrogen, 20% oxygen + 80% nitrogen, 15% oxygen + 85% nitrogen, and 10% oxygen + 90% nitrogen. Retinal haemodynamic variables and systemic haemodynamics were measured during all inhalation periods. Recordings under resting conditions were performed three times to calculate intraclass coefficients.
In two subjects we did not obtain technically adequate results. A dose dependent change in retinal blood flow during graded oxygen breathing was observed (p < 0.001). During 100% oxygen breathing blood flow decrease was between 29% and 33%, whereas blood flow increase was between 28% and 33% during inhalation of 10% oxygen + 90% nitrogen.
Scanning laser Doppler flowmetry has an acceptable reproducibility and is appropriate for description of the effect of graded changes in PO2 on retinal haemodynamics. The main problems with the system are the large zero offset, the fixation during retinal scanning, and the neglect of blood flow changes during the cardiac cycle.
目的/背景：最近生产出了一种商用扫描激光多普勒血流仪，它能提供视网膜灌注的二维图。本研究的目的是调查这些测量的可重复性和敏感性。
在一项双盲交叉研究中，16名健康受试者被随机分配吸入不同比例的氧气和氮气混合气体。给予以下氧气和氮气混合气体：100%氧气 + 0%氮气、80%氧气 + 20%氮气、60%氧气 + 40%氮气、40%氧气 + 60%氮气、30%氧气 + 70%氮气、20%氧气 + 80%氮气、15%氧气 + 85%氮气和10%氧气 + 90%氮气。在所有吸入阶段测量视网膜血流动力学变量和全身血流动力学。在静息状态下进行三次记录以计算组内相关系数。
在两名受试者中，我们未获得技术上足够的结果。观察到在分级吸氧期间视网膜血流呈剂量依赖性变化（p < 0.001）。在吸入100%氧气时，血流减少29%至33%，而在吸入10%氧气 + 90%氮气时，血流增加28%至33%。
扫描激光多普勒血流测量法具有可接受的可重复性，适用于描述PO2分级变化对视网膜血流动力学的影响。该系统的主要问题是零偏移大、视网膜扫描时的固定以及忽略心动周期中的血流变化。
