Skov AG, Rives AS, Freiberg J, et al. - In this systematic review, researchers sought to examine the comparative effectiveness and safety of preserved vs preservative-free beta-blockers and beta-blocker-containing combination eye drops in patients with glaucoma or ocular hypertension. The primary outcome was a change in intraocular pressure (IOP) from baseline to final follow-up, whereas secondary outcomes involved ocular and systemic side effects, and other clinical and quality of life outcomes. The sample consisted of 1,125 patients. There was no clinically significant difference in mean IOP change between the preserved and preservative-free treatments. Data on adverse events were collected using various methods and were reported in an incomplete manner. Although some ocular surface health measures favoured preservative-free medications, more research is needed. The increased use of preservative-free drops may be associated with improved ocular surface and tolerability, but strong evidence from randomized clinical trials would be appreciated.