Long-Term Birth Control Pill Use May Increase Risk of Glaucoma

A recent study shows that women using birth control pills for three years or more could have twice the risk of developing glaucoma late in life.

Yet researchers from the University of California, San Francisco, Duke University School of Medicine and Third Affiliated Hospital Nanchang University, Nanchang, China, found that estrogen levels seen in longer use of contraceptive pill methods could increase the risk of the eye condition.

Researchers theorize that women who are not on the pill have variations of natural estrogen levels go up and down, which seems to prevent the eye from developing glaucoma. Yet women on the pill experience more consistent estrogen levels that could potentially cause the condition to develop or worsen over time.

The researchers looked at data on more than 3,400 women aged 40 and older across the United States who answered questionnaires regarding  their reproductive health and eye exams.

"We believe at this point, by analyzing the data, there is an association between long-term birth control use and glaucoma," said Elaine Wang, of Duke University and an author of the study, via CNN. "Why? We're not sure. The next step is to examine the eyes carefully and look at exactly what is happening to a woman's vision when she's on birth control pills. We need to verify these findings."

While researchers note that more studies need to be completed in order to make a connection between long-term oral contraceptive use and an increase in glaucoma, many believe that health officials should check patient's medical history to see if they have a family history of glaucoma. 

However, Dr. Stephen Sisson, the executive director of Ambulatory Services at the Johns Hopkins hospital, emphasizes that contraceptives also carry other health risks, as well.

"Pregnancy itself carries significant health risks," Sisson said, via ABC News. "There are other significant risks of oral contraceptives-including blood clots, heart attacks and strokes-that are considered more serious than glaucoma." 

Statistics from the Guttmacher Institute show that approximately 62 percent of all women of reproductive age are currently using a contraceptive method.