The risk of obstructive airways disease in a glaucoma population.

BACKGROUND: Asthma and chronic obstructive pulmonary disease (COPD), defined as obstructive airways disease (OAD), are two common chronic conditions especially in the elderly. Glaucoma is also a common disease in the elderly with a prevalence close to 5% among those older than 75 years. Most medical therapy for glaucoma is given as eye drops. It has been described that small amounts of systemically absorbed beta-blockers can produce significant respiratory adverse events in predisposed patients.
METHODS: Population-based cohort study with nested case-control analysis using the UK General Practice Research Database (GPRD). We studied the prevalence of OAD in a cohort of patients 60 to 85 years old with a first ever diagnosis of glaucoma and compared it to the prevalence in an age- and sex-matched cohort sampled from the general population. We also calculated the RR and 95% CI of worsening asthma in non-severe asthma patients among the two cohorts. Incidence of OAD was studied in a cohort of glaucoma patients 60 to 85 years old and in an age- and sex-matched cohort from the general population.
RESULTS: The prevalence of OAD was the same between the glaucoma cohort and the general population (OR 1.1; 95% CI 0.9-1.4). The risk of worsening asthma associated with glaucoma was OR 1.2 (95% CI 0.5-2.8). The incidence of OAD was similar in both cohorts. Current users of ophthalmic drugs presented a RR of 1.2 (95% CI 0.8-1.9) of developing asthma compared to non-users in the glaucoma population. The risk in the first month of treatment with topical beta-blockers was 2.1 (95% CI 0.7-6.7). DISCUSSION: We did not find an association between glaucoma and OAD. Use of topical glaucoma medication was not associated with a major increased risk of asthma.