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 (> or =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 may be biased and highlights the need to study these relationships prospectively.