The complex interaction between ocular perfusion pressure and ocular blood flow - Relevance for glaucoma
The complex interaction between ocular perfusion pressure and ocular blood flow - Relevance for glaucoma
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DOI：
10.1016/j.exer.2010.09.002
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发表时间：
2011-08-01
影响因子：
3.4
通讯作者：
Schmetterer, Leopold
中科院分区：
文献类型：
--
作者：
Schmidl, Doreen;Garhofer, Gerhard;Schmetterer, Leopold
青光眼是一种原因不明的视神经病变。这种疾病最重要的危险因素是眼压升高。降低眼压与减少青光眼的进展有关。最近的几项大规模试验表明，低眼灌注压(OPP)是该病发生、流行和进展的危险因素。这是一个强有力的迹象，表明血管因素参与了这种疾病的发病机制，这是150年前提出的一个假说。然而，由于一种被称为自动调节的现象，OPP和流向眼睛后极的血液之间的关系是复杂的。自动调节过程试图保持血流恒定，尽管OPP发生了变化。虽然在眼部血管系统的许多实验中已经观察到了自动调节，但面对OPP的变化，潜在的血管扩张剂和血管收缩反应的机制仍然很不清楚。然而，最近有证据表明，与吸盘引起的眼压变化相比，在等长运动引起的血压变化期间，人类脉络膜对血流的调节更好。这可能会对我们对青光眼的理解产生影响，因为它表明血流调节不仅强烈依赖于OPP，而且还取决于眼压水平本身。事实上，有数据表明，通过药物干预降低眼压可以改善视神经头部的血流调节，而不依赖于眼睛血管扩张的作用。(C)2010爱思唯尔有限公司。保留所有权利。
Glaucoma is an optic neuropathy of unknown origin. The most important risk factor for the disease is an increased intraocular pressure (IOP). Reducing IOP is associated with reduced progression in glaucoma. Several recent large scale trials have indicated that low ocular perfusion pressure (OPP) is a risk factor for the incidence, prevalence and progression of the disease. This is a strong indicator that vascular factors are involved in the pathogenesis of the disease, a hypothesis that was formulated 150 years ago. The relation between OPP and blood flow to the posterior pole of the eye is, however, complex, because of a phenomenon called autoregulation. Autoregulatory processes attempt to keep blood flow constant despite changes in OPP. Although autoregulation has been observed in many experiments in the ocular vasculature the mechanisms underlying the vasodilator and vasoconstrictor responses in face of changes in OPP remain largely unknown. There is, however, recent evidence that the human choroid regulates its blood flow better during changes in blood pressure induced by isometric exercise than during changes in IOP induced by a suction cup. This may have consequences for our understanding of glaucoma, because it indicates that blood flow regulation is strongly dependent not only on OPP, but also on the level of IOP itself. Indeed there is data indicating that reduction of IOP by pharmacological intervention improves optic nerve head blood flow regulation independently of an ocular vasodilator effect. (C) 2010 Elsevier Ltd. All rights reserved.