Blacks with open-angle glaucoma (OAG) have a higher risk of cardiovascular mortality, according to a study in the March issue of Archives of Ophthalmology. Open-angle glaucoma is especially prevalent in populations of African origin, say the studys authors.

The study, an arm of the Barbados Eye Studies, examined the long-term mortality rate of 4,092 black participants in Barbados, aged 40 to 84 years. Three hundred individuals were diagnosed with OAG at baseline;141 of these had previously received treatment.

At the nine-year follow-up examination, the researchers learned that 764 (19%) participants had died. They concluded that mortality risk was not independently associated with OAG. Yet, the researchers discovered that subjects who were either previously diagnosed with or treated for glaucoma had a 38% higher overall risk of dying from cardiovascular disease. More importantly, participants medicated with timolol maleate eye drops had a 91% higher risk for death from cardiovascular disease.

However, upon closer investigation, there was no association between mortality and OAG after controlling for cardiovascular risk factors, age and gender, says Michael Sullivan-Mee, O.D., clinical instructor at the Albuquerque VA Medical Center. Although a greater percentage of glaucoma subjects died compared to non-glaucoma subjects in the nine-year period, this was mostly explained by differences in age, gender and coexisting cardiovascular disease.

Also, I am not at all convinced that there is a direct relationship between timolol use and morbidity, Dr. Sullivan-Mee says. This study was not well-designed to address a relationship between mortality and timolol use, and was not able to account for a multitude of factors that could have affected the results, such as adherence, comorbibity of other systemic diseases, and interactions with other medications.

Finally, because few white subjects were analyzed in this study, Dr. Sullivan-Mee believes no absolute conclusions can be made about race and OAG-related mortality. While some interpolations [about the association between race and OAG-related mortality] can be assumed, no direct comparisons are possible.

Wu SY, Nemesure B, Hennis A, et al. Open-angle glaucoma and mortality: The Barbados Eye Studies. Arch Ophthalmol 2008 Mar;126(3):365-70.