14 DAY TRIAL // Scientists at the University of Michigan, led by ophthalmology professor Dr. Joshua Stein, have determined in a new study that women who are on estrogen-only hormone replacement therapy for menopause-related symptoms also experience a decreased risk of developing glaucoma.
The latter is a fairly common form of eye disease, consisting of several related conditions. All these illnesses are characterized by intraocular pressure-associated optic neuropathy (pain inside the eye). If left untreated, glaucoma often leads to reduced visual acuity, as well as permanent blindness.
Taking estrogen for hormonal rebalancing following menopause apparently decreases the risk women have of developing glaucoma, the team has found. However, the exact molecular mechanisms involved in this effect are still unknown, the National Library of Medicine reports. The NLM is a part of the US National Institutes of Health (NIH).
“Ours is one of the first [… study] to find estrogen-containing hormone-replacement therapy was associated with a reduction in glaucoma risk,” says Stein. For this research, the expert analyzed data pertaining to 152,000 women, of which 60,000 had prescriptions for estrogen-only therapy.
Between 2001 and 2009, roughly 2 percent of all women in the study developed a common form of glaucoma called primary open angle glaucoma. Statistically, for each month women in the second group took estrogen, their risk of developing the eye disorder dropped by 0.4 percent.
That is the equivalent of a 19 percent drop in risk over just 4 years, Stein explains. He is, however, careful to add that this investigation did not prove a cause-and-effect correlation between estrogen intake and reduced glaucoma risks. In other words, it is still possible that other factors played a role in averting this condition as well.
“The findings are most helpful in guiding research in drug development for hormone-based therapies to be used as neuro-protective agents,” comments Massachusetts Eye and Ear Infirmary glaucoma specialist Dr. Angela Turalba, who reviewed the new research.
Details of the study were published in the January 30 issue of the scientific journal JAMA Ophthalmology. The paper suggests that estrogen might be producing these beneficial effects by either lowering intraocular pressure, or by protecting certain types of cells inside the eye against degeneration.