Obese women are less likely to develop glaucoma

Obesity may be associated with higher eye pressure and a reduced risk of open-angle glaucoma in women, but not men, according to a report posted online today that will appear in the may issue of the archives of Ophthalmology, one of the JAMA/Archives Journals.

"Open-angle glaucoma is a chronic eye disease characterized by glaucomatous optic neuropathy and corresponding glaucomatous Visual field loss," the authors write as background information in the article. Previous research has identified several risk factors for open-angle glaucoma, including the intraocular pressure (pressure in the eye), age, gender, cause myopia (nearsightedness) and ethnicity.

Wishal deceased Ramdas, M.D., m SC., of the Erasmus medical centre, Rotterdam, Netherlands, and colleagues examined data from the 3,939 participants in the Rotterdam study. This population-based study included participants 55 years and over living in a suburb of Rotterdam, Netherlands, which had no open-angle glaucoma when the study began between 1991 and 1993.

In the course of an average of 9.7 years of follow-up developed 108 participants (2.7 percent) open-angle glaucoma. Those who developed the condition were considerably older, more often had high myopia (nearsightedness serious) and were often more male, compared with those who did not. No statistically significant effect of socio-economic status, smoking or alcohol intake was found on the development of open-angle glaucoma.

Among women, there was a significant association between higher body mass index and intraocular pressure. Each increase of one unit of the body mass index, however, was associated with a 7% decreased risk of the development of open-angle glaucoma. These associations, were not present among men.

Excess fat tissue place increasing pressure on the eye sockets, resulting in pressure in the eye, the authors note. The higher intraocular pressure among obese women should have led to an increased risk for glaucoma. "However, this effect was not observed and so the multivariate analysis provided a protective effect of body mass index over open-angle glaucoma incidence in women," they write. "Another explanation could be that high estrogen levels and hormone therapy might be protective to open-angle glaucoma, and obesity seems positively associated with plasma postmenopausal estrogen levels."

"Obesity seems to be associated with a higher intraocular pressure and a lower risk of developing open-angle glaucoma," conclude the authors. "These associations were only present in women. Other lifestyle-related factors, such as the socio-economic status, smoking and alcohol use, were not associated with open-angle glaucoma. "