Postmenopausal estrogen use, type of menopause, and lens opacities - The Framingham studies

Background: Previous studies of estrogen replacement therapy and lens opaci ties have not reported consistent findings. Objective: To investigate whether postmenopausal estrogen use is associated with the occurrence of age-related lens opacities (nuclear, cortical, and posterior subcapsular). Methods: Surviving members of the original cohort of the Framingham Heart S tudy who also participated in the Framingham Eye Study (1986-1989) were exa mined for the absence or presence of lens opacities. Data from the Framingh am Heart Study, including information on menopausal status (collected bienn ially from approximately 1948) and use of estrogen replacement therapy (col lected biennially from approximately 1960) were used to examine association s between lens opacities and duration of postmenopausal estrogen use, type of menopause, and age at menopause. Five hundred twenty-nine women, aged 66 to 93 years, were included. Multivariable-adjusted odds ratios of specific types of lens opacities were calculated for (1) duration of estrogen use ( never and 1-2, 3-9, and greater than or equal to 10 years), (2) surgical vs natural menopause, and (3) age at menopause. Results: Longer duration of postmenopausal estrogen therapy was inversely a ssociated with the presence of nuclear lens opacities in an adjusted model. Women who had taken estrogen for 10 years or longer had a 60% reduction in risk compared with nonusers (odds ratio, 0.4; 95% confidence interval, 0.2 -1.01). Longer duration of estrogen use was associated with fewer posterior subcapsular opacities at a borderline level of significance. No associatio n was noted fur cortical opacities. The risk of posterior subcapsular opaci ties was significantly increased for women who had undergone surgical menop ause compared with women with natural menopause (odds ratio, 2.2; 95% confi dence interval, 1.1-4.3). No association was noted for lens opacities and a ge at menopause. Conclusion: Data from our study and other studies suggest that a reduction in the risk of lens opacities may be an additional benefit of postmenopausa l estrogen use.