Nutritional Manipulation of Primate Retinas, V: Effects of Lutein, Zeaxanthin, and n-3 Fatty Acids on Retinal Sensitivity to Blue-Light-Induced Damage

PURPOSE. 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. METHODS. 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-mu m-diameter exposures of low-power 476-nm laser light at 0.5 mm (similar to 2 degrees) eccentricity, which is adjacent to the macular pigment peak, and parafoveally at 1.5 mm (similar to 6 degrees). 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. RESULTS. 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. CONCLUSIONS. 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. (Invest Ophthalmol Vis Sci. 2011;52: 3934-3942) DOI:10.1167/iovs.10-5898