RETINAL BLOOD FLOW MEASUREMENT

这项拟议研究的目的是完善和测试我们的 视网膜血流测量的新方法--荧光泡 系统，该系统使用扫描激光检眼镜和数字图像 能够记录和数字化视频血管造影照片的分析系统， 观察含有亚淬灭浓度的 染料通过视网膜大循环、黄斑和视神经乳头 微循环和脉络膜血管。为此，我们建议 以下具体目的：1）确定体外最有效的 为了使荧光最大化， 的囊泡，使用视网膜血管模型，以评估各种 囊泡大小、染料和染料浓度的组合; 2）确定 囊泡的大小、磷脂成分、电荷和结构 脂质体影响荧光素的存活时间和清除率 囊泡从循环通过体内测试首先在兔眼 然后在猴子的眼睛; 3）映射正常视网膜中的血流， 使用荧光囊泡系统的非人类灵长类动物;追踪 明确定义的荧光囊泡在由以下物质构建的覆盖物上的移动 连续的视频帧将允许计算血液的速度 视网膜、黄斑、视神经乳头、视网膜的大小血管中的血流， 和脉络膜; 4）研究药物对血液动力学的反应， 一种改变血液粘度的药物（葡聚糖）和一种引起 非人灵长类动物视网膜血管舒张（山莨菪碱）;变化 可以同时和客观地监测这些因素产生的 整个视网膜大循环和黄斑微循环; 以及5）使用以下方法绘制正常非人灵长类动物眼睛中的脉络膜血流 荧光囊泡系统;两种荧光囊泡 将使用分别用两种染料包封。荧光 囊泡系统克服了扫描激光检眼镜的局限性 来测量血流量。它允许客观测量血流 在任何大小的容器中的速度。糖尿病视网膜病变是致盲的眼睛 涉及视网膜血流的疾病。并发症的诊断 糖尿病视网膜病变的发展，以及评估 治疗的有效性，如药物和全视网膜 光凝固，可以通过使用荧光囊泡系统来改善。 视神经乳头毛细血管可改善青光眼的治疗 用这种方法提供的血流数据。视网膜中央动脉危象 静脉阻塞也可以通过测定视网膜血流来诊断， 允许治疗开始更早。

The objective of this proposed study is the refinement and testing of our new approach to retinal blood flow measurement, the fluorescent vesicle system, which uses a scanning laser ophthalmoscope, and a digital image analysis system capable of recording and digitizing video angiograms to view the movement of vesicles containing a subquenched concentration of dye through the retinal macrocirculation, the macular and optic nerve head microcirculation, and the choroidal vessels. To this end, we propose the following specific aims: 1) to determine in vitro the most efficient concentrations of encapsulated dyes in order to maximize the fluorescence of the vesicles, using a model of retinal vessels to evaluate various combinations of vesicle size, dye and dye concentration; 2) to determine how vesicle size, phospholipid composition, charge, and structure of the liposomes affect the survival time and clearance of the fluorescent vesicles from the circulation by testing in vivo first in the rabbit eye and then in the monkey eye; 3) to map blood flow in the normal retina in a nonhuman primate using the fluorescent vesicle system; tracing the movement of well-defined fluorescent vesicles on overlays constructed from successive video frames will allow calculation of the velocity of blood flow in large and small vessels of the retina, macula, optic nerve head, and choroid; 4) to investigate hemodynamic responses to a pharmacological agent that alters blood viscosity (dextran) and a drug that causes vasodilation (anisodamine) in the nonhuman primate retina; changes produced by these agents can be monitored simultaneously and objectively in the entire retinal macrocirculation and the macular microcirculation; and 5) to map choroidal blood flow in a normal nonhuman primate eye using the fluorescent vesicle system; two kinds of fluorescent vesicles separately encapsulated with two dyes will be used. The fluorescent vesicle system overcomes the limitations of scanning laser ophthalmoscopy in measuring blood flow. It allows objective measurement of blood flow velocity in any size vessel. Diabetic retinopathy is a blinding eye disease involving retinal blood flow. Diagnosis of complications of diabetes before retinopathy develops, as well as evaluating the effectiveness of treatments such as pharmacological agents and panretinal photocoagulation, may be improved by using the fluorescent vesicle system. Management of glaucoma may be improved with optic nerve head capillary blood flow data provided with this approach. Impending central retinal vein occlusion can also be diagnosed by determining retinal blood flow, allowing treatment to begin earlier.