Commonly used to treat multiple cardiovascular diseases, systemic beta blockers have a more limited a role in IOP reduction, given their cardiopulmonary side effects. Researchers investigated whether topical glaucoma eye drops—beta blockers in particular—exhibited weaker IOP-lowering efficacy in patients also taking systemic beta blockers.

To evaluate whether IOP elevation following medication washout is influenced by systemic beta blocker use, the researchers analyzed pre-randomized data from the HORIZON study. Eligible subjects had age-related cataract and POAG; their medicated IOP was ≤31mm Hg on one to four topical glaucoma drops. The researchers analyzed data from two study visits prior to cataract surgery.

A total of 781 eyes of 781 subjects was included, 15.9% of whom were taking systemic beta blockers. The majority (82.2%) used cardioselective beta blockers. The researchers found no statistically or clinically significant difference in IOP increase following washout based on systemic beta blocker use: a 6.8mm Hg increase in subjects taking systemic beta blockers and 6.7mm Hg in those who were not. In addition, for patients taking a systemic beta blocker, the IOP increase was similar following washout, regardless of the number of topical glaucoma eye drops they were using.  

They surmise that the vast majority of patients on a systemic beta blocker will still achieve more than 75% of IOP lowering on average when using a topical beta blocker as part of their medical regimen. Use of a systemic beta blocker did not meaningfully affect IOP lowering effectiveness of glaucoma drops. “Withholding a topical beta blocker from these patients, therefore, seems unwarranted,” they noted.