New York, NY - New data suggest there is an increased risk of death and cardiovascular death among black patients with diagnosed and treated open-angle glaucoma (OAG), as well as similar risks among these patients with ocular hypertension. Treatment with timolol maleate was particularly problematic, with use of the beta blocker associated with a 70% increased risk of death and a 91% increased risk of cardiovascular mortality.

The findings are from the large Barbados Eye Study, a National Eye Institute-funded study of a predominantly black population. Investigators, led by Suh-Yuh Wu (Stony Brook University, New York), along with senior investigator Dr Cristina Leske (Stony Brook University), say that while OAG alone was not associated with increased mortality, patients treated at baseline tended to have increased mortality after nine years of follow-up, underscoring "the importance of close monitoring and controlling of adequate intraocular pressure levels in this and other high-risk populations."

"Our study results suggested an excess mortality, mostly cardiovascular-related, in persons with ocular hypertension and also in persons with known OAG, particularly in those who were treated with timolol maleate, as compared with their counterparts," Wu commented to heartwire. "This comparison involved the evaluation of relative risks, and therefore, our results do not imply that treated OAG or ocular hypertension posed a risk while untreated OAG did not."

In their paper, published in the March 11, 2008 issue of the Archives of Ophthalmology, the authors note that OAG, the most common type of glaucoma, is prevalent in populations of African origin. Information on the relationship between glaucoma and death would have particular clinical and public-health advantages in black populations, as this group has higher rates of chronic disease mortality, higher intraocular pressures, and a higher prevalence/incidence of OAG than white populations.

Slightly more than 4000 participants, average age 58 years, were assessed between 1987 and 1992. At baseline, 300 participants had glaucoma, including 141 who had been diagnosed and treated. After nine years of follow-up, 764 of the participants had died. In a multivariate-adjusted model, OAG was not associated with all-cause or cardiovascular mortality. The risk of death, however, was significantly higher in patients diagnosed with and treated for OAG, with a particular risk observed for those treated with timolol maleate.

Wu told heartwire that approximately 60% of patients taking medication at baseline to reduce intraocular pressure were taking timolol, either alone or in combination. She said the findings involving the beta blocker are limited by the observational study design but do warrant further study. Future trials, she said, could provide more definitive answers regarding the advisability to stop certain medications or the use of alternative treatment for high intraocular pressure.

"While side effects of beta blockers such as timolol could contribute to early deaths, its association with mortality could be a marker for longer duration of treatment and/or more advanced glaucoma, rather than being due to the medication itself," she noted.