Age-related macular degeneration (AMD) and Alzheimer's disease (AD) are neurodegenerative conditions that afflict millions of elderly people around the world. AMD is a progressive retinal disorder tha Show more
Age-related macular degeneration (AMD) and Alzheimer's disease (AD) are neurodegenerative conditions that afflict millions of elderly people around the world. AMD is a progressive retinal disorder that leads to central vision loss whereas AD primarily causes cognitive decline and behavioral changes. While each disease has distinct clinical manifestations, the accumulation of extracellular amyloid-β is a common histopathologic finding. Similarly, cerebral amyloid angiopathy (CAA), a vascular condition that can exist independent or with AD, is characterized by the accumulation of amyloid-β in cerebral blood vessels. While significant investigation of the pathophysiologic links between AMD and AD has been conducted, the underlying similarities and differences in the pathobiology of AMD and CAA has not been considered. In this review, we discuss the common pathological features of these two conditions. We then discuss the similar pathobiology that involves cholesterol metabolism, apolipoprotein E, amyloid-β, and complement mediated inflammation. At the same time, we discuss key differences in their pathobiology. This discussion sheds new perspective and insights of their pathobiology. Show less
To investigate genetic determinants of macular pigment optical density in women from the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative Obse Show more
To investigate genetic determinants of macular pigment optical density in women from the Carotenoids in Age-Related Eye Disease Study (CAREDS), an ancillary study of the Women's Health Initiative Observational Study. 1585 of 2005 CAREDS participants had macular pigment optical density (MPOD) measured noninvasively using customized heterochromatic flicker photometry and blood samples genotyped for 440 single nucleotide polymorphisms (SNPs) in 26 candidate genes related to absorption, transport, binding, and cleavage of carotenoids directly, or via lipid transport. SNPs were individually tested for associations with MPOD using least-squares linear regression. Twenty-one SNPs from 11 genes were associated with MPOD (P ≤ 0.05) after adjusting for dietary intake of lutein and zeaxanthin. This includes variants in or near genes related to zeaxanthin binding in the macula (GSTP1), carotenoid cleavage (BCMO1), cholesterol transport or uptake (SCARB1, ABCA1, ABCG5, and LIPC), long-chain omega-3 fatty acid status (ELOVL2, FADS1, and FADS2), and various maculopathies (ALDH3A2 and RPE65). The strongest association was for rs11645428 near BCMO1 (βA = 0.029, P = 2.2 × 10(-4)). Conditional modeling within genes and further adjustment for other predictors of MPOD, including waist circumference, diabetes, and dietary intake of fiber, resulted in 13 SNPs from 10 genes maintaining independent association with MPOD. Variation in these single gene polymorphisms accounted for 5% of the variability in MPOD (P = 3.5 × 10(-11)). Our results support that MPOD is a multi-factorial phenotype associated with variation in genes related to carotenoid transport, uptake, and metabolism, independent of known dietary and health influences on MPOD. Show less