Abstract
Purpose: :
To study the effects of n-3 fatty acids, lutein and zeaxanthin on the distribution of lipofuscin in the retinal pigment epithelium (RPE).
Methods: :
Seventeen rhesus monkeys, 7-18 years of age, were fed xanthophyll-free semipurified diets with either low or adequate amount of n-3 fatty acids from birth and had no macular pigment. Five were supplemented with lutein and six with zeaxanthin for 6 to 24 months while six remained on the xanthophyll-free diet. Following sacrifice, the central retina was sectioned at 2 µm along the vertical meridian through the fovea. Fluorescent images of the central retinal sections were taken with Texas Red and/or FITC filter sets. The areas occupied by the autofluorescent lipofuscin granules of the RPE were measured along the vertical meridian from zero to 2.64 mm eccentricity and compared with data from age-matched control monkeys (n = 7) fed a standard laboratory diet.
Results: :
In animals fed the xanthophyll-free diet low in n-3 fatty acids, the RPE accumulated more lipofuscin and at a faster rate with advancing age than control animals (p 0.1).
Conclusions: :
Long-term dietary deprivation of n-3 fatty acids, in the absence of lutein and zeaxanthin, increased the accumulation of lipofuscin in the parafoveal RPE. Shorter-term supplementation with zeaxanthin or lutein did not reverse this effect. Reduction in lipofuscin levels is one mechanism by which n-3 fatty acids may confer protection from age-related macular disease.
Keywords: ipofuscin • macular pigment • lipids