Medications May Be Less Effective Outside Clinical Trials for Glaucoma Patients

Although clinical trials have indicated that intraocular pressure (IOP)-lowering medications are effective in patients with open-angle glaucoma, new research suggests that the medications may not be as effective in real-world settings.

The study, published in the April 2014 issue of JAMA Ophthalmology, assessed the effectiveness of IOP-lowering medications in patients with primary open-angle glaucoma who were taking up to 3 medications from multiple ophthalmology clinics. IOP was measured while patients were using their usual medication to lower IOP. Patients then washed out all IOP-lowering drops, and pressure was measured again 2 to 4 weeks later.

The results indicated that discontinuation of IOP-lowering medications was associated with a significant increase in IOP. After medication washout, pressure increased on average by 5.4 mm Hg among patients taking 1 medication, 6.9 mm Hg among those using 2 medications, and 9 mm Hg for those using 3 medications.

However, a substantial proportion of patients only experienced small changes in IOP after medication washout. After medication discontinuation, IOP increased by <25% among 38% of patients using 1 medication, 21% of those taking 2 medications, and 13% of those using 3 medications.

The results suggest “either that [patients] were not using the medication effectively or that the medication itself, although used properly, was not lowering the IOP,” the study authors conclude.