Birth Control Use Linked With Raised Glaucoma Risk

Taking birth control pills for more than 3 years may double a woman’s risk of developing glaucoma, according to preliminary research presented this week at the 117th Annual Meeting of the American Academy of Ophthalmology in New Orleans.

The results of this population-based, cross-sectional study further support the findings of previous research determining that estrogen may play a significant role in the pathogenesis of glaucoma, a leading cause of blindness.

The Nurses’ Health Study, for example, found an increased incidence of glaucoma development over a 10-year follow-up period among participants who had used oral contraceptives for at least 5 years.

“Our findings help to confirm the potential role of female hormones in the health of the optic nerve and the retinal ganglion cells, the structures that are damaged in glaucoma,” senior study author Shan C. Lin, MD, Professor of Clinical Ophthalmology and Director of the Glaucoma Service, University of California San Francisco School of Medicine, told Consultant360.

To determine whether an association between birth control pills use and the presence of glaucoma exists, Lin and colleagues examined data from 3406 women aged 40 years and older living throughout the United States who were participating in the 2005-2008 National Health and Nutrition Examination Survey. These women had been taking oral contraceptives for anywhere from months to decades.

The study participants underwent eye examinations and completed questionnaires that included inquiries regarding their vision and reproductive health. The questionnaire did not distinguish between different types of oral contraceptives, such as progestin-only birth control pills and combination birth control pills (containing both estrogen and progestin).

After adjusting for potential confounders including age, ethnicity, existing health problems, and history of eye problems, researchers found that women who had used any type of birth control pill for longer than 3 years were 2.05 times more likely to report a diagnosis of glaucoma.

Although their study does not provide definitive proof that birth control pills cause glaucoma, it does indicate that the long-term use of oral contraceptives may be a potential risk factor for glaucoma. Researchers therefore recommend that gynecologists and ophthalmologists consider informing their patients who are long-term users of birth control pills to be screened for glaucoma if they also have other risk factors, such as African American ethnicity or a family history of glaucoma.

“Future large population studies should continue to examine the role of oral contraceptives in glaucoma development,” said Lin. In addition, he noted that large prospective studies involving women can include careful documentation of oral contraceptive use and incorporate eye examinations for glaucoma.

-Meredith Edwards White

Reference

Want YE, Tabaldi D, Wang SY, Lin SC. Association Between Oral Contraceptive Use and Glaucoma in the United States. Poster presented at the 2013 Annual Meeting of the American Academy of Ophthalmology. http://www.nxtbook.com/tristar/aao/final_program2013/index.php#/232. Poster 339.