Patients who are black have an increased risk of death from cardiovascular diseases if they have high pressure in the eyes or if they have been diagnosed with and treated for glaucoma, according to a report in the March 2008 issue of Archives of Ophthalmology, one of the JAMA/Archives journals.
Glaucoma is a group of eye diseases that involve damage to the optic nerve. The most common symptom is a raised pressure of the eye itself. “[It] is one of the leading causes of visual impairment worldwide,”according to the authors of the article. “The most common type, primary open-angle glaucoma, is especially prevalent in populations of African origin, in which it is the foremost cause of blindness.” Additionally, black populations have higher rates of death from chronic disease and ocular hypertension, or high pressure within the eyes, than do white populations.
To assess the relationship of this correlation of mortality and glaucoma Suh-Yuh Wu, M.A., of Stony Brook University, Stony Brook, New York, and colleagues studied approximately 4,000 participants between the ages of 40 and 84, with an average age of 58.6 years, in the Barbados Eye Studies. This assessment focuses on a predominantly black population which has an ancestry similar to that of African Americans. The initial visits were completed between 1987 and 1992. In the exams, and height, weight, blood pressure were noted; interviews were performed; and several eye measurements were taken, including photographs of the retina and eye pressure measurements.
At the inception of the study, 300 patients had glaucoma, including 141 who had been diagnosed and treated. Nine years after follow-up, 19% of the subjects had died. Adjusting for other factors, overall death was not associated with glaucoma. However, death for cardiovascular related reasons was:
- 38% higher in patients previously diagnosed with or treated for open-angle glaucoma
- 91% higher in those who had been treated with the beta-blocker timolol maleate
- 25% higher in those with ocular hypertension at the start of the study
The authors provide a potential interpretation of these results: “One explanation for the excess mortality [death] found in persons with previously diagnosed open-angle glaucoma could be their longer duration of disease compared with those with newly diagnosed disease,” they say. “Another explanation for an increased mortality risk could be related to the open-angle glaucoma treatment received.” Beta-blockers and other medications used to treat glaucoma could affect the cardiovascular system and increase the risk of death.
There is additional evidence that links the risk factors for ocular hypertension and cardiovascular disease — this could clarify the increased rick of death associated with ocular hypertension. “These findings underscore the importance of close monitoring and controlling of adequate intraocular pressure levels in this and other high-risk populations,” conclude the authors.
Open-angle Glaucoma and Mortality: The Barbados Eye Studies
Suh-Yuh Wu, MA; Barbara Nemesure, PhD; Anselm Hennis, PhD, FRCP; Andrew P. Schachat, MD; Leslie Hyman, PhD; M. Cristina Leske, MD, MPH; for the Barbados Eye Studies Group
Arch Ophthalmol. 2008;126(3):365-370.
Written by Anna Sophia McKenney