Hormone replacement therapy, reproductive factors, and the incidence of cataract and cataract surgery: the Blue Mountains Eye Study.

The authors aimed to assess the relation between endogenous and exogenous female hormones and the incidence of age-related cataract and cataract surgery. The Blue Mountains Eye Study examined 2,072 women aged 49 years or older during 1992-1994, of whom 1,343 (74.0% of survivors) were reexamined after 5 years, during 1997-1999. Information on reproductive factors and use of hormone replacement therapy was collected using an interviewer-administered questionnaire. Lens photographs were graded for the presence of cortical, nuclear, and posterior subcapsular cataract at baseline and follow-up. Women who had ever used hormone replacement therapy had a decreased incidence of cortical cataract affecting any eye compared with never users (odds ratio = 0.7, 95% confidence interval: 0.4, 1.0). However, this was not statistically significant (odds ratio = 0.7, 95% confidence interval: 0.4, 1.1) when using the first affected eye. Older age at menarche was associated with an increased incidence of cataract surgery (odds ratio = 2.6, 95% confidence interval: 1.2, 5.7) and a significant trend for increasing incidence of nuclear cataract (p = 0.04). There was also a significant trend for decreasing incidence of cataract surgery with increasing duration of reproductive years (p = 0.009). These epidemiologic data provide some evidence that estrogen may play a protective role in reducing the incidence of age-related cataract and cataract surgery.