Department of Ophthalmology, University Hospital of Grenoble, Joseph Fourier University, Grenoble, France.
Retina. 2010 Feb;30(2):275-80. doi: 10.1097/iae.0b013e3181b85f18.
To evaluate the effect of hemodilution on subfoveal choroidal blood flow in the human eye with or without retinal vein occlusion.
Choroidal blood flow was measured using laser Doppler flowmetry in 28 patients with retinal vein occlusion in 1 eye. Isovolemic hemodilution was performed when hematocrit was >35%. Laser Doppler flowmetry parameters, velocity, volume, and flow were measured in both eyes in 4 sessions: 1 hour before and 1 hour after the first hemodilution on Day 1 and Day 7.
Hematocrit decreased significantly by 23.7%, 19.8%, and 16.1% in the first hour, on the first day, and the seventh day after hemodilution, respectively (P < 0.001). The ocular perfusion pressure of the healthy eye and the eye with retinal vein occlusion decreased by 7.7% and 7.2% after 1 hour and by 5.3% and 4.7% 1 day after hemodilution, respectively (P < 0.01). After hemodilution, subfoveal choroidal blood velocity, volume, flow, and vascular resistance did not significantly change in either eye.
Laser Doppler flowmetry measurement in the subfoveal choroid is a feasible technique for blood flow assessment in patients with retinal vein occlusion. A substantial change of hematocrit after isovolemic hemodilution does not lead to a significant change in choroidal blood flow. Vascular regulation is expected to keep blood flow constant and needs to be further explored.
评估血液稀释对伴有或不伴有视网膜静脉阻塞的人眼中心凹下脉络膜血流的影响。
对 28 例单侧视网膜静脉阻塞患者的 1 只眼采用激光多普勒血流仪测量脉络膜血流。当红细胞压积（Hct）>35%时，进行等容血液稀释。在 4 个时间段，共 4 个阶段，分别于第 1 天和第 7 天的首次血液稀释前 1 小时和稀释后 1 小时，测量双眼的激光多普勒血流仪参数，包括速度、容量和流量。
血液稀释后 1 小时、第 1 天和第 7 天，Hct 分别显著下降 23.7%、19.8%和 16.1%（P<0.001）。健康眼和视网膜静脉阻塞眼的眼内灌注压在血液稀释后 1 小时分别下降 7.7%和 7.2%，1 天后分别下降 5.3%和 4.7%（P<0.01）。血液稀释后，无论是健康眼还是视网膜静脉阻塞眼，中心凹下脉络膜血流速度、容量、流量和血管阻力均无显著变化。
激光多普勒血流仪测量中心凹下脉络膜血流是评估视网膜静脉阻塞患者血流的一种可行技术。等容血液稀释后 Hct 显著变化不会导致脉络膜血流的显著变化。血管调节有望使血流保持恒定，需要进一步探讨。
