Macular pigment density and age-related maculopathy in the carotenoids in age-related eye disease study - An ancillary study of the women's health initiative

Purpose: To examine the association between intermediate age-related macular degeneration (AMD) and the optical density of macular pigment (MPOD), which is composed of lutein and zeaxanthin from the diet. Design: Cross-sectional cohort study. Participants: We included 1698 of 2005 women ages 54 to 86 years and participating in the Carotenoids in Age-Related Eye Disease Study, an ancillary study of the Women's Health Initiative. Methods: The MPOD was measured noninvasively by heterochromatic flicker photometry. Fundus photographs were taken to document prevalent AMD. Main Outcome Measures: Intermediate AMD (n = 305) and two subtypes-large drusen (n = 233) and pigmentary abnormalities (n = 157). Results: After adjusting for covariates, the odds ratio (OR) and 95% confidence interval (CI) for AMD among women in quintile (Q) 5 (n = 339) versus 1 (n = 340) for MPOD was 1.4 (0.9, 2.1). However, after excluding women with possible unstable diets and recent supplement use due to chronic disease history, associations reversed (OR Q2-5 vs. 1, 0.8; 95% CI, 0.5-1.2), but remained nonsignificant. Associations also differed between middle-aged (54-69 years) and older ( 70 years) women (P-interaction = 0.09), but less so, after excluding women who were likely to have unstable diets: adjusted ORs (95% CI) were 0.5 (0.3-1.0; P = 0.08) for intermediate AMD among middle-aged women (n = 516) with MPOD in Q2 to Q5 versus 1 and 1.0 (0.5-2.0; P = 0.90) for older women (n = 422). Conclusions: The MPOD is not cross-sectionally associated with AMD. The inconsistency of relationships across age groups and in subgroups of women who are likely to have more stable diets suggests that cross-sectional associations maybe biased and highlights the need to study these relationships prospectively.