Michelson G, Harazny J
Department of Ophthalmology, University Erlangen-Nürnberg, Erlangen, Germany.
Ophthalmology. 1997 Apr;104(4):659-63. doi: 10.1016/s0161-6420(97)30255-3.
The authors quantified the vascular resistance for venous outflow in central retinal vein occlusion (CRVO).
The blood velocity in the central retinal vein (CRV) and central retinal artery (CRA) was measured by pulsed Doppler sonography (4-Mhz probe), and the pulse curve of the intraocular pressure (IOP) was evaluated by pneumotonometry. With multichannel data acquisition and storage software, the velocity-pulse curve of the CRV and CRA, the IOP-pulse curve, the arterial blood pressure, and the electrocardiogram were measured simultaneously in real-time mode. The relationships between the pulse curves of the blood velocity in the CRV and CRA and the IOP were calculated off-line. The onset time, the time of half maximum, and the time to the maximum of the pulse curves were evaluated. A relative index R' for the retinal outflow resistance was calculated by R' = deltaIOP/deltaVcrv. The authors examined 23 eyes of 23 patients with CRVO not older than 2 weeks and 23 eyes of 23 age-matched controls. There was no significant difference between the mean age of the control group (46 +/- 16 years) and that of the CRVO group (54 +/- 20 years).
In eyes with CRVO, the authors found significantly lower systolic, diastolic, and mean outflow velocity. The amplitude of the CRV velocity pulse was significantly decreased compared with control eyes. In CRVO, the mean CRV velocity pulse amplitude (deltaVvein) was 1.77 +/- 1.0 cm/second, and in controls, it was 2.08 +/- 0.61 cm/second (P < 0.005). There was no significant difference in the mean IOP, but the IOP pulse amplitude (deltaIOP) was significantly higher in CRVO compared with controls (deltaIOP: CRVO 2.82 +/- 1.45 mmHg, control 1.96 +/- 0.56 mmHg, P < 0.005). The relative resistance index R' for venous outflow was significantly increased in eyes with CRVO (2.0 +/- 1.1 mmHg/cm/sec) compared with controls (1.1 +/- 0.44 mmHg/cm/s, P < 0.001).
In eyes with CRVO, the systolic, diastolic, and mean velocity and the amplitude of the CRV velocity-pulse curve were significantly decreased and the resistance for retinal venous outflow was significantly increased compared with controls.
作者对视网膜中央静脉阻塞（CRVO）时的视网膜静脉流出道血管阻力进行量化。
采用脉冲多普勒超声（4-MHz探头）测量视网膜中央静脉（CRV）和视网膜中央动脉（CRA）的血流速度，用气眼压计评估眼内压（IOP）的脉搏曲线。使用多通道数据采集和存储软件，以实时模式同时测量CRV和CRA的速度-脉搏曲线、IOP-脉搏曲线、动脉血压和心电图。离线计算CRV和CRA血流速度的脉搏曲线与IOP之间的关系。评估脉搏曲线的起始时间、半最大值时间和最大值时间。通过R' = ΔIOP/ΔVcrv计算视网膜流出阻力的相对指数R'。作者检查了23例病程不超过2周的CRVO患者的23只眼以及23例年龄匹配的对照组的23只眼。对照组的平均年龄（46±16岁）与CRVO组的平均年龄（54±20岁）之间无显著差异。
在CRVO患者的眼中，作者发现收缩期、舒张期和平均流出速度显著降低。与对照眼相比，CRV速度脉搏的幅度显著降低。在CRVO患者中，CRV速度脉搏平均幅度（ΔVvein）为1.77±1.0厘米/秒，而在对照组中为2.08±0.61厘米/秒（P<0.005）。平均IOP无显著差异，但与对照组相比，CRVO患者的IOP脉搏幅度（ΔIOP）显著更高（ΔIOP：CRVO组为2.82±1.45 mmHg，对照组为1.96±0.56 mmHg，P<0.005）。与对照组（1.1±0.44 mmHg/cm/s，P<0.001）相比，CRVO患者眼中静脉流出的相对阻力指数R'显著升高（2.0±1.1 mmHg/cm/sec）。
与对照组相比，CRVO患者眼中的收缩期、舒张期和平均速度以及CRV速度-脉搏曲线的幅度显著降低，视网膜静脉流出阻力显著增加。
