(SAN FRANCISCO) - While estrogen's ability to prevent bone loss and heart disease in postmenopausal women is established, here's something new: estrogen may benefit the eyes. A study in the June issue of Ophthalmology found a reduced incidence of lens opacities, precursors of age-related cataract, in postmenopausal women taking estrogen.
Although hardening and clouding of the eye's lens occur normally with age, a cataract is characterized by excessive lens opacity. One of the leading causes of blindness in the United States, age-related cataract affects approximately 13 million Americans age 40 and older. Scientists have long suspected that hormones may play a role in the development of age-related cataract because the condition is more common in women than in men.
Author Jose M. Benitez del Castillo, MD, PhD and colleagues from the Instituto de Investigaciones Oftalmologicals Ramon Castroviejo (Madrid, Spain) recruited nineteen postmenopausal women taking estrogen for more than four years, twenty postmenopausal women reporting no estrogen use, and twenty-three men. All study participants were similar in both age and visual acuity and were free of ocular and systemic diseases, including glaucoma and diabetes.
Researchers examined the eyes of study participants using fluorophotometry, a technique used to determine the rate of fluid flow in the eye. They found that the group of women taking estrogen had significantly decreased lens opacity relative to the other two groups.
According to study authors, "these data are suggestive of a beneficial effect of postmenopausal estrogen use on lens transmission in women." Authors also state that "a protective effect of estrogens on lens transparency could have beneficial effects on quality of life for older women and would have implications for providing ophthalmic care."
A previous study of 43 participants (Klein et al., Archives of Ophthalmology, vol. 112, Jan 1994) has also supported a link between estrogen use and lens opacity in women.
Ophthalmology is the journal of the American Academy of Ophthalmology.