Purpose: The purpose of this study was to explore the relation between age at menarche, parity, and oral contraceptive (OC) use, and primary open-angle glaucoma (POAG).
Methods: We followed 79 440 women in the Nurses' Health Study prospectively from 1980 to 2006 and identified 813 cases of incident POAG. Eligible participants were ≥40 years old, free of POAG at baseline, had information on reproductive history, and reported receiving eye examinations during follow-up. Relevant exposure data and POAG risk factors were updated using biennial questionnaires. We used proportional hazards models to calculate multivariable rate ratios (MVRRs) of POAG and 95% confidence intervals (CI).
Results: In multivariable analysis, there were no significant linear trends between age at menarche (P for trend=0.65) or reproductive duration defined as time between age at menarche and menopause (P for trend=0.30) and POAG. Although ever using OCs was not associated with POAG risk (MVRR=1.14; 95% CI, 0.98, 1.34), ≥5 years of OC use was associated with a modest 25% increased risk of POAG (MVRR=1.25; 95% CI, 1.02, 1.53; P for linear trend=0.04). Furthermore, among past OC users, a shorter time since stopping OC use was also associated with an increased risk of POAG (P for linear trend=0.02). Parity was not associated with POAG risk.
Conclusion: The ≥5 years of OC use was associated with a modestly increased risk of POAG. These data add further support for a role of circulating estrogen in the pathogenesis of POAG.