Despite the increase in glaucoma medication use recorded in several other developed countries, researchers found that topical intraocular pressure (IOP)-lowering medication use in the United States remained stable from 1999 to 2014, which they note may be due to the differential performance of other procedures.

Researchers conducted a series of eight nationally representative surveys of United States residents every two years from 1999 to 2014, asking adults over age 40 if they have used or taken a prescribed medication in the past month. The team found no change in the number of Americans using topical IOP-lowering medications, with 1.4% of survey takers on the medications between 1999 and 2000, as well as 2013 and 2014. They note that while the number of drugs per patient remained unchanged, there was a significant increase in the use of prostaglandin analogs and combination medications and a decrease in the use of beta-blockers.

“The United States experience appears to be different from other nations in not having either an increase in the number of residents on topical IOP-lowering medication or an increase in the number of medications per user,” the study authors wrote. “This effect is particularly remarkable as Medicare part D was implemented in 2006 in the middle of this study period and increased the coverage for prescription drugs among Medicare beneficiaries.”