Does Postmenopausal Estrogen Replacement Therapy Reduce Lens Opacities

BACKGROUND: Postmenopausal estrogen use affects many organ systems. It's impact on the development of cataracts is unclear. PURPOSE: To examine whether postmenopausal estrogen replacement therapy is associated with the occurrence of lens opacities, a precursor to cataract formation. METHODS: 553 women, aged 66 to 93 years, participated in the Framingham Eye Study (1986 to 1989) and had menopausal and lifetime estrogen use data available from Framingham Study biennial exams conducted from 1948 to 1990. Lens opacities were determined by two certified examiners who evaluated lens status by means of dilated pupils and the use of a standardized grading system. The presence or absence of a lens opacity and the anatomical location of the lens opacity (nuclear, cortical, posterior-subcapsular) were recorded. Multivariate logisitic regression adjusting for potential confounders including age, body mass index, hypertension, diabetes, smoking was used to evaluate the association between estrogen use and lens opacity. RESULTS: In multivariate analysis, use of postmenopausal estrogens for ≥10 years was inversely associated with the presence of all types of lens opacities (OR 0.5, 95% CI 0.2, 1.0). Women who had used estrogen for ≥10 years had a 60% reduction in risk of nuclear lens opacities compared with non-users (OR 0.4, 95% CI 0.2, 0.9). An association of borderline statistical significance was seen for longer duration estrogen use and fewer posterior subcapsular opacities (OR 0.3, 95% CI 0.1–1.0), and no association between estrogen therapy and cortical opacities was observed. Age of menopause, comparing early (age 23–44) and late (greater than age 54 years) to normal (age 45 to 53 years) was not associated with any type of lens opacities nor was type of menopause (natural compared to surgical). CONCLUSION: Our study suggests that long term estrogen use was associated with a reduction in overall, nuclear and posterior-subcapsular lens opacities; thereby suggesting that estrogen may be protective in cataract formation.