Abstract
Purpose:
Creation of a virtual model of macular pigment development from a data set of carotenoid levels in macaque retinas was undertaken to provide insight into the metabolic origin of R,S-zeaxanthin and the time-line of accumulation of the macular carotenoids.
Methods:
Macaque retinas were collected post-mortem from animals at the Oregon Primate Research Center. Sections were 2, 4, or 8 mm punches centered on the macula. Analysis of retinal sections for carotenoids was performed quantitatively by reversed-phase HPLC using UV-vis detection. Separation of zeaxanthin isomers was carried out using chiral column HPLC.
Results:
A linear regression fit for each of the macular carotenoids in retinal sections from macaques ranging in age from 133 days gestation to >10 years yields equations for the quantitative levels of carotenoids, lutein, R,R-zeaxanthin, R,S-zeaxanthin, S,S-zeaxanthin as a function of age. All carotenoid levels were shown to increase with increasing age but differential rates of increase were observed which lead to a variation in carotenoid ratios with age.
Conclusions:
Ratios of carotenoids vary with increasing age in the retina and are well modeled by a linear fit of individual carotenoid levels within retinal sections. Regression data for the levels of R,S-zeaxanthin are consistent with conclusion that this carotenoid is absent from the retina prior to birth and is formed in the retina from lutein. The rate of accumulation R,R-zeaxanthin in the macula is greater than that of the other carotenoids.
Keywords: 444 carotenoids/carotenoid binding proteins •
587 macular pigment •
585 macula/fovea