Nov. 18 (UPI) -- Women who have taken birth control pills are twice as likely to suffer from glaucoma -- a leading cause of blindness.
Reviewing data from the Centers for Disease Control's National Health and Nutrition Examination Survey, researchers from University of California-San Francisco, Duke University and Third Affiliated Hospital of Nanchang University reported an increased risk of the eye disease in women no matter what kind of oral contraceptive they used.
They presented their findings today at the 117th Annual Meeting of the American Academy of Ophthalmology in New Orleans.
"At this point, women who have taken oral contraceptives for three or more years should be screened for glaucoma and followed closely by an ophthalmologist, especially if they have any other existing risk factors," said Shan Lin, lead researcher and professor of clinical ophthalmology at the University of California San Francisco.
The research looked at more than 3,000 women above age 40 who were asked to complete reproductive health and eyesight tests. Even when researchers took other risk factors into consideration, oral contraceptives corresponded to increased occurrence of glaucoma.
The authors note that the study does not indicate oral contraceptives directly cause glaucoma, rather, researchers hope that it will be included in the the risk profile for glaucoma, along with existing risk factors including family history. Previous studies have shown that estrogen may play a significant role in glaucoma.
Dr. Stephen Sisson, executive director of Ambulatory Services at the Johns Hopkins Hospital, said women have to look at the the "big picture" when factoring in the health risks linked to contraceptives and pregnancy.
“Pregnancy itself carries significant health risks,” Sisson said, adding, “There are other significant risks of oral contraceptives -- including blood clots, heart attacks, and strokes -- that are considered more serious than glaucoma.”
According to the Glaucoma Research Foundation, an estimated 2.2 million Americans have glaucoma but only half of those know they have it.
[American Academy of Opthalmology] [ABC News]