Researchers in Sweden have examined the intraocular pressure (IOP)-lowering effect of adding brimonidine as a fourth anti-glaucoma medication to the pre-existing therapy of three topical drugs.

The retrospective, register-based cohort study analyzed 53 individuals using glaucoma medications who then used brimonidine as their fourth drug. After 46 days of treatment, almost half of the 46 participants who could tolerate the therapy reached the target IOP reduction of 17%. After a one-year period, 53% of the eligible group had a sustained, uneventful effect and a mean IOP decrease of 20%.

During the one-year follow-up, 39% of the eligible study participants discontinued the treatment, mostly due to insufficient treatment effect that led to a change in treatment or filtering surgery.

The study concludes that brimonidine’s addition as the fourth adjunctive anti-glaucoma drop could be a valuable option for a minority of patients.