Pennsylvania College of Optometry, Salus University, Elkins Park, Pennsylvania, USA.
Invest Ophthalmol Vis Sci. 2011 Jun 6;52(7):3934-42. doi: 10.1167/iovs.10-5898.
Blue-light photooxidative damage has been implicated in the etiology of age-related macular degeneration (AMD). The macular pigment xanthophylls lutein (L) and zeaxanthin (Z) and n-3 fatty acids may reduce this damage and lower the risk of AMD. This study investigated the effects of the lifelong absence of xanthophylls followed by L or Z supplementation, combined with the effects of n-3 fatty acid deficiency, on acute blue-light photochemical damage.
Subjects included eight rhesus monkeys with no lifelong intake of xanthophylls and no detectable macular pigment. Of these, four had low n-3 fatty acid intake and four had adequate intakes. Control subjects had typical L, Z, and n-3 fatty acid intake. Retinas received 150-μm-diameter exposures of low-power 476-nm laser light at 0.5 mm (∼2°) eccentricity, which is adjacent to the macular pigment peak, and parafoveally at 1.5 mm (∼6°). Exposures of xanthophyll-free animals were repeated after supplementation with pure L or Z for 22 to 28 weeks. Ophthalmoscopically visible lesion areas were plotted as a function of exposure energy, with greater slopes of the regression lines indicating greater sensitivity to damage.
In control animals, the fovea was less sensitive to blue-light-induced damage than the parafovea. Foveal protection was absent in xanthophyll-free animals but was evident after supplementation. In the parafovea, animals low in n-3 fatty acids showed greater sensitivity to damage than animals with adequate levels.
After long-term xanthophyll deficiency, L or Z supplementation protected the fovea from blue light-induced damage, whereas adequate n-3 fatty acid levels reduced the damage in the parafovea.
蓝光光氧化损伤与年龄相关性黄斑变性（AMD）的病因有关。黄斑色素叶黄素（L）和玉米黄质（Z）和 n-3 脂肪酸可能会减轻这种损伤，降低 AMD 的风险。本研究调查了终生缺乏叶黄素，随后补充 L 或 Z，以及 n-3 脂肪酸缺乏的影响，对急性蓝光光化学损伤的影响。
研究对象包括 8 只终生未摄入叶黄素且黄斑色素无法检测到的恒河猴。其中 4 只摄入低 n-3 脂肪酸，4 只摄入足够的 n-3 脂肪酸。对照组具有典型的 L、Z 和 n-3 脂肪酸摄入量。视网膜接受低功率 476nm 激光光的 150μm 直径暴露，在 0.5mm（约 2°）偏心处，接近黄斑色素峰值，以及在 1.5mm（约 6°）旁视网膜处。叶黄素缺乏动物在补充纯 L 或 Z 22 至 28 周后重复暴露。用暴露能量作为函数绘制眼科学可见病变区域，回归线的斜率越大，表明对损伤越敏感。
在对照动物中，黄斑区对蓝光诱导的损伤比旁黄斑区更不敏感。叶黄素缺乏动物的黄斑区没有保护作用，但补充后就有了。在旁黄斑区，n-3 脂肪酸水平低的动物比 n-3 脂肪酸水平足够的动物对损伤更敏感。
长期缺乏叶黄素后，L 或 Z 补充可保护黄斑免受蓝光诱导的损伤，而足够的 n-3 脂肪酸水平可减少旁黄斑区的损伤。
