Postmenopausal women who take hormone therapy are likely to reduce their risk of developing age-related macular degeneration (AMD), a new study has found.
Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among older adults.
"Although genetics plays a key role in susceptibility to AMD, environmental factors, such as smoking, are also important," wrote the authors.
"Evidence of higher rates of AMD in women than in men and links between AMD and cardiovascular disease suggested a role for estrogen in the etiology" or development of the condition," they added.
The study led by Diane Feskanich, Sc.D., of Brigham and Women's Hospital and Harvard Medical School, Boston examined the data of 74,996 post-menopausal women in the Nurses' Health Study.
They looked at estrogen-related factors such as postmenopausal hormone use, past use of oral contraceptives, ages at first period and menopause and childbirth history in.
Around 554 of the women developed early (beginning-stage) AMD and 334 women developed neovascular (more advanced, involving the formation of new blood vessels) AMD between 1980 and 2002.
"Current postmenopausal hormone users had a notable 48 percent lower risk of neovascular AMD compared with those who had never used postmenopausal hormones, although risk did not decline linearly with longer durations of use," the authors said.
"Risk was lowest for postmenopausal hormone users who had used oral contraceptives in the past," they further added.
They also found that the risk of early AMD was 34 percent higher among current postmenopausal hormone users and oral contraceptive use was not associated with early AMD risk.
The report appears in the April issue of Archives of Ophthalmology, one of the JAMA/Archives journals.