JAN 13, 2009
The article examines the relationship between topical b-blockers and mortality with particular reference to cardiovascular disease. Three previously published studies, which also examined the topic, are also referenced. The Early Manifest Glaucoma Trial, and the Ocular Hypertensive Treatment Study found no decrease in survival in patients using b-blockers, however the Blue Mountain study did report an association between the use of topical timolol and cardiovascular mortality. The possible reason for this finding may be the effect of timolol on the lipids, namely the increase of low-density lipoproteins that is thought to yield a higher incidence of coronary events.
The present study, investigated the associations between long-term and short -term use of topical b- blockers on mortality as well as the effect on serum lipid levels. The study utilized the participants of the Rotterdam Study, a prospective, population- based cohort study of all residents 55 years and older living in a suburb of Rotterdam (3842 total participants, 484 were β-blocker users). This allowed careful and accurate collection of the significant data. The long-term effects examined the association between topical b-blocker use before and at baseline, between 1990 and1997, and mortality between1997 and 2005. The short-term effects were defined as death within three months of initiating topical b-blocker use. Both arms of the study used age- matched controls from the same Rotterdam study.
Neither the long-term study, nor the short-term study demonstrated an effect on mortality as a result of topical b-blocker use. The study also indicated that the use of b-blockers did not influence serum HDL cholesterol levels. All results were adjusted for age and gender.
The authors make some interesting observations. The reason for examining the short-term effects of b-blocker use was to account for mortality that may arise from asthma attacks or systemic hypotension. They also point out that an earlier report on systemic timolol showed a reduction in mortality in patients using it. The conclusion being that any possible deleterious effects from systemic timolol on blood lipids did not cancel out its protective effects.
Although the report showed no relationship between cardiovascular disease and topical b blockers, it did use a specific population group that had a low incidence of cardiovascular disease, and this may be a confounding factor which needs to be examined when applying these results to a different population.
Dr. Freedman has no financial interests to disclose.