Reflectance Method for Measuring Macular Pigment

测量黄斑色素的反射法

• 批准号: 7391787
• 负责人: RICHARD A. BONE
• 金额: $ 9.3万
• 依托单位: FLORIDA INTERNATIONAL UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7391787
• 关键词: Age related macular degeneration; Antioxidants; Biological Availability; Carotene; Carotenoids; Clinical Trials; Computer software; Data; Dietary Supplementation; Dose; Effectiveness; Evaluation; Eye; Eye diseases; Fundus; Goals; High Pressure Liquid Chromatography; Image; Image Analysis; Intervention Studies; Intervention Trial; Lutein; Maps; Measurement; Measures; Melanins; Methods; Minor; Modification; Monitor; Onset of illness; Photometry; Pigments; Placebos; Play; Rate; Recruitment Activity; Reporting; Research; Retina; Retinal; Risk; Role; Serum; Staging; Supplementation; System; Techniques; Testing; Time; Vision; Vitamins; Zinc; age related; aging population; base; compare effectiveness; day; density; design; dietary supplements; innovation; macula; prevent; response; skills; zeaxanthin

There is evidence for an inverse association between the amount of macular pigment (MP) in the retina and risk of age-related macular degeneration (AMD). Dietary supplementation with lutein (L) or zeaxanthin (Z) can significantly increase MP density. These findings are relevant to an intervention study, the long-term goal of this research, to determine the efficacy of L and Z in preventing or delaying AMD. Heterochromatic flicker photometry (HFP) is a commonly used method for measuring MP density, but HFP is not suitable for many subjects, particularly those whose vision is impaired by AMD. Specific aim 1 is to develop a simple, inexpensive, objective, reflectance method of measuring MP density, suitable for an L or Z intervention study. The method will utilize a retinal camera equipped with a triple-band interference filter. The system will be designed so that 3 fundus images at different wavelengths may be extracted from a single image. Image analysis software will be used to generate an MP density map from these images. The wavelengths will be chosen to minimize the potential influence of photopigments and melanin on the measured densities. The validity of the technique will be investigated by comparing MP densities obtained by HFP and by the new reflectance method. Specific aim 2 is to compare the effects of L and Z supplementation, at 20 mg per day for 6 months, on L and Z concentration in the blood serum and on the density of MP determined by the reflectance method. Fifty subjects will participate. On a random basis, 20 will be assigned to each of the supplements and 10 will be assigned to a placebo. For a subset, HFP will also be used to monitor changes in MP density for comparison with reflectance data. The concentration of L and Z in the serum will be measured by HPLC. The study will quantify differences in response to supplementation in subjects, and will seek causes. Preliminary data indicate that the rate of increase in MP is driven by the serum concentration of L+Z. Specific aim 3 is to compare the reflectance and HFP methods for subjects with early-stage AMD. On average, such subjects may be expected to have below normal MP densities. Fourteen subjects will participate in a similar L trial to that in specific aim 2. The trial will permit evaluation of the reflectance method in subjects for whom HFP is likely to prove unsuitable. It will also determine their responsiveness to L supplementation.

有证据表明视网膜中黄斑色素（MP）的量与年龄相关性黄斑变性（AMD）的风险之间存在负相关性。膳食补充叶黄素（L）或玉米黄质（Z）可以显着增加MP密度。这些发现与一项干预研究有关，该研究的长期目标是确定L和Z在预防或延迟AMD方面的疗效。异色闪烁光度法（HFP）是测量MP密度的常用方法，但HFP不适用于许多受试者，特别是那些视力受到AMD损害的受试者。具体目标1是开发一种简单、廉价、客观、反射率测量MP密度的方法，适用于L或Z干预研究。该方法将利用配备有三波段干涉滤光片的视网膜照相机。系统将 可以被设计为使得可以从单个图像中提取不同波长的3个眼底图像。将使用图像分析软件根据这些图像生成MP密度图。将选择波长以最小化色素和黑色素对测量密度的潜在影响。该技术的有效性将通过比较由HFP和新的反射率方法获得的MP密度进行研究。具体目标2是比较L和Z补充，每天20毫克，持续6个月，对血清中L和Z浓度和对MP密度的影响，通过反射法测定。将有50名受试者参与。在随机基础上，20人将被分配到每种补充剂，10人将被分配到安慰剂。对于一个子集，HFP也将用于监测MP密度的变化，以与反射率数据进行比较。血清中L和Z的浓度将为 通过HPLC测量。该研究将量化受试者对补充剂反应的差异，并将寻找原因。初步数据表明，MP的增加速率由L+Z的血清浓度驱动。具体目标3是比较早期AMD受试者的反射率和HFP方法。平均而言，这些受试者可能预期具有低于正常的MP密度。14例受试者将参加与特定目标2相似的L试验。该试验将允许在可能证明不适合HFP的受试者中评价反射率方法。它还将决定他们对L补充剂的反应。