Adherence and Persistence to Medical Therapy in Glaucoma: An Overview

Glaucoma is a group of progressive optic neuropathies characterized by loss of retinal ganglion cells and visual field deterioration. Despite the fact that the underlying pathophysiology of glaucoma remains unknown, elevated intraocular pressure (IOP) is a well-established risk factor, and the only factor that can be modified. Robust evidence from epidemiological studies and clinical trials has clearly demonstrated the benefits of IOP control in reducing the risk of glaucoma progression. IOP-lowering therapy by the means of eye drops remains a first-line treatment option. However, like other chronic and asymptomatic conditions, many patients with glaucoma have difficulties in maintaining high rates of adherence persistence to prescribed medications. On average, patients with chronic medical conditions take 30-70% of the prescribed medication doses, and on average 50% discontinue medications in the first months of therapy. The ophthalmic literature shows similarly low rates of adherence to treatment. Indeed, poor adherence is associated with disease progression and increased complication rates, as well as healthcare costs. The present review analyzes and discusses the causes of variability of the adherence to the prescribed drugs. The education of patients about glaucoma and the potential consequences of insufficient adherence and persistence seems fundamental to maximize the probability of treatment success and therefore prevent visual disability to avoid unnecessary healthcare costs.