Menopausal and reproductive factors and risk of age-related macular degeneration

Objective: To investigate whether estrogen exposures are associated with lower risks of age-related macular degeneration (AMD). Methods: Postmenopausal hormone (PMH) use, past use of oral contraceptives (OCs), ages at menarche and menopause, and parity were assessed among 74 996 postmenopausal women. Over 22 years, cases of early (n = 554) and neovascular (n=334) AMD with a visual acuity of 20/30 or worse were identified. Cox models were used to calculate the relative risk for each exposure, adjusted for smoking and other factors. Results: Current PMH users had a notable 48% lower risk of neovascular AMD compared with those who had never used PMH, although risk did not decline linearly with longer durations of use. Risk was lowest for PMH users who had used OCs in the past (P value for interaction, .03). In contrast, risk of early AMD was a notable 34% higher among current PMH users and OC use was unassociated with risk. The only remarkable finding for the endogenous estrogenic factors was a 26% lower risk of early AMD for parous women. Conclusions: Although PMH and OC use were associated with a lower risk of neovascular AMD, no benefit was observed for early AMD. Factors influencing lifetime exposure to estrogens were not consistently associated with the disease.