INTRARETINAL OXYGEN CONSUMPTION AND THE PREVENTION OF HYPOXIA IN RETINAL ISCHEMIA

为视网膜提供充足的氧气对正常的视觉功能至关重要。氧气通常是由支持视网膜的两个循环系统中的血液提供的。这些是脉络膜循环，位于视网膜后面，和视网膜循环，支持视网膜的前半部分。视网膜循环特别容易受到血管疾病和血流不足（缺血）的影响。血管改变涉及广泛的视网膜疾病，目前在我们的社区负责大多数新的失明。脉络膜循环是相对稳健的，并提供了一个潜在的途径，增加氧气输送到视网膜缺血性疾病的临床管理。这种方法的可行性在很大程度上取决于视网膜的氧气需求，以及视网膜缺血对氧气需求的影响。我们计划找出在正常情况下视网膜内的许多不同层消耗了多少氧气，然后确定在缺血情况下这是如何变化的。然后我们看看是否可以通过提高血液含氧量，增加脉络膜血流量，减少视网膜外层的氧气用量来提供足够的氧气。我们的实验将在实验室大鼠身上进行，但同样的原理也很容易转移到人类身上，如果它们被证明对保护视网膜免受缺血性损伤有益的话。我们的研究还将量化血液中的氧含量与视网膜不同层中的氧含量之间的关系。这一信息可能在其他视网膜疾病的治疗和预防中证明是有价值的，其中视网膜内氧环境的操纵是一个令人兴奋的新研究途径。

Adequate oxygen supply to the retina is critical for normal visual function. The oxygen is normally supplied by the blood flowing in the two circulations that support the retina. These are the choroidal circulation, lying behind the retina, and the retinal circulation, which supports the front half of the retina. The retinal circulation is particularly vulnerable to vascular disease and insufficient blood flow (ischemia). Vascular changes are involved in a wide range of retinal diseases which are currently responsible for the majority of new blindness in our community. The choroidal circulation is relatively robust, and offers a potential avenue for increasing oxygen delivery to the retina in the clinical management of ischemic retinal diseases. The feasibility of such an approach is strongly dependent on the oxygen requirements of the retina, and how this is influenced by retinal ischemia. We plan to find out how much oxygen is consumed by the many different layers within the retina under normal conditions and then determine how this changes under ischemic conditions. We will then see if we can supply enough oxygen from the choroid by a combination of raising the oxygen content of the blood, increasing choroidal blood flow, and reducing the amount of oxygen used by the outer half of the retina. Our experiments will be done in laboratory rats, but the same principles are readily transferable to humans if they prove to be beneficial in protecting the retina from ischemic damage. Our study will also quantify the relationship between oxygen levels in the blood stream, and those in the different layers of the retina. This information may prove valuable in the treatment and the prevention of other retinal diseases where the manipulation of the intraretinal oxygen environment is an exciting new avenue of research.