Chen H C, Gupta A, Wiek J, Kohner E M
Diabetic Retinopathy Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, England, UK.
Ophthalmology. 1998 May;105(5):772-5. doi: 10.1016/S0161-6420(98)95013-8.
The authors studied the changes in retinal blood flow (RBF) and oxygen reactivity in a major temporal vein in patients with central retinal vein occlusion (CRVO).
Eleven patients with nonischemic CRVO approximately 7 weeks from onset of disease.
Laser Doppler velocimetric measurement of RBF and vessel reactivity to inhaling 60% oxygen. Measurements were performed at baseline and 3 months.
Flow velocity in the affected eye had increased significantly by 3 months, from 1.6 +/- 0.4 cm/second to 2.0 +/- 0.4 cm/second (P = 0.02). Retinal blood flow, however, remained unchanged (13.7 +/- 5.8 microl/minute versus 15.0 +/- 6.5 microl/minute). The two comparable RBF values, despite differing velocity values, suggest that the relatively normal baseline value was achieved through higher intravascular pressure at baseline (Bernoulli's principle). This is supported by the fact that oxygen reactivity had improved from 2.1% +/- 3.6% at baseline to 3.8% +/- 3.1% (P = 0.001) at 3 months, which suggests an improved ability to respond to hyperoxia from reduced intravascular pressure.
Intravascular pressure in CRVO appears to continue to decrease during the first 5 months after the onset of CRVO, indicating continuing reduction in the degree of outflow obstruction during this time.
作者研究了视网膜中央静脉阻塞（CRVO）患者主要颞静脉的视网膜血流（RBF）和氧反应性变化。
11例非缺血性CRVO患者，发病约7周。
采用激光多普勒测速法测量RBF以及吸入60%氧气时血管的反应性。在基线期和3个月时进行测量。
患眼的血流速度在3个月时显著增加，从1.6±0.4厘米/秒增至2.0±0.4厘米/秒（P = 0.02）。然而，视网膜血流量保持不变（13.7±5.8微升/分钟对15.0±6.5微升/分钟）。尽管速度值不同，但这两个可比的RBF值表明，相对正常的基线值是通过基线时较高的血管内压力实现的（伯努利原理）。这一观点得到以下事实的支持：氧反应性从基线时的2.1%±3.6%提高到3个月时的3.8%±3.1%（P = 0.001），这表明血管内压力降低后对高氧的反应能力有所改善。
CRVO发病后的前5个月内，血管内压力似乎持续下降，表明在此期间流出道阻塞程度持续减轻。
