Review the clinical manifestations and treatment of primary open-angle glaucoma (POAG).Articles indexed in PubMed, Scopus, and Cochrane Library in the last 10 years using the key words "glaucoma," "open-angle glaucoma," and "'open-angle glaucoma' AND 'treatment.'" Primary sources were used to locate additional resources. ClinicalTrials. gov was used to locate unpublished studies.Eighty-one publications were reviewed and criteria supporting the primary objective were used to identify useful resources.The literature included practice guidelines, review articles, original research articles, and product prescribing information for POAG.The POAG optic neuropathies result in optic disk damage and visual field loss. Ophthalmic medication therapy retards glaucoma progression, but many older patients require multiple medications to preserve vision and quality of life. An agent from the ophthalmic prostaglandin analog class is used as initial therapy in current practice because of the convenience of once-a-day administration and lower incidence of systemic side effects and slightly increased efficacy compared with other available ophthalmic medication classes. The other ophthalmic medication classes used in clinical practice include the beta-adrenergic blocking agents, the alpha-2 adrenergic agonists, and the carbonic anhydrase inhibitors. Proper ophthalmic eye-drop administration and medication adherence are imperative for preserving vision in POAG. Selective laser trabeculoplasty is a viable alternative to ophthalmic medications either initially or if a patient experiences ocular or systemic side effects from medication therapy. A modified prostaglandin analog was approved by the Food and Drug Administration in November 2017; its role in clinical practice is still evolving.