Glaucoma associated with increased risk of cardiovascular death in black patients

Mar 12 2008

In a population of African origin, persons with diagnosed and treated glaucoma appeared to have an increased risk of death from cardiovascular causes, according to a study by Suh-Yuh Wu, and colleagues in the Departments of Preventive Medicine and Ophthalmology at Stony Brook University, the University of the West Indies, and the Cleveland Clinic Foundation.

The study results are published in the March issue of Archives of Ophthalmology.

Glaucoma is one of the leading causes of visual impairment worldwide. The most common type, primary open-angle glaucoma, is especially prevalent in populations of African origin, including African-Americans, in which it is the foremost cause of blindness. According to Wu and coauthors, populations of African origin have higher rates of death from chronic disease than white populations and also tend to have and higher eye pressure (ocular hypertension).

Wu and colleagues studied 4,092 participants age 40 to 84 (average age 58.6) in the Barbados Eye Studies, which assessed a predominantly black population with similar ancestry to African-Americans. Initial visits occurred between 1987 and 1992. Height, weight and blood pressure were recorded. Interviews were conducted, and eye photographs and various eye measurements were taken, including eye pressure. Participants with specific findings were also referred for a comprehensive ophthalmologic examination.

At the beginning of the study, 300 participants had glaucoma, including 141 who had been diagnosed and treated. After nine years of follow-up, 764 (19 percent) of the participants had died. After adjusting for other factors, the researchers found that glaucoma was not associated with the risk of death overall. However, the risk of death from cardiovascular diseases was 38 percent higher in individuals with a previous diagnosis or treatment for open-angle glaucoma and 91 percent higher in those treated with one particular beta-blocker agent. Cardiovasular deaths were also 28 percent higher in those with ocular hypertension at the beginning of the study.

The researchers write in “Open-angle Glaucoma and Mortality” that “one explanation for the excess mortality found in persons with previously diagnosed open-angle glaucoma could be their longer duration of disease compared with those with newly diagnosed disease.” They also point out that another explanation could be related to the open-angle glaucoma treatment that patients received, as beta blockers and other medications used to treat open-angle glaucoma may harm the cardiovascular system and increase death risk.

The authors conclude that their research findings underscore the importance of careful monitoring and controlling of adequate intraocular pressure levels in the study population, and other high-risk populations. Close monitoring of treatment to lower the intraocular pressure and correction of its complications, they suggest, may prevent early deaths.