What rates of glaucoma progression are clinically significant?

Introduction: Clinically important rates of glaucoma progression (worsening) are ones that put a patient at risk of future functional impairment or reduction of vision-related quality of life (VRQoL). Most treated eyes do not progress at rates that will lead to future visual impairment, but there are a significant proportion (3-17%) of eyes, that are at risk of impairment even under clinical care. While very fast rates of progression (e.g. MD progression of -1.5 dB/year) are generally problematic, much slower rates also may be deleterious for young patients, particularly those diagnosed with late disease. Areas covered: This review provides an overview of what we know about rates of glaucomatous visual field and structural loss. It also summarizes the literature on what stage of vision loss affects vision related quality of life, and the value of predicting functional impairment based on life expectancy and severity of the disease. Expert commentary: It is important to consider life expectancy, disease severity and vision-related quality of life based treatment targets to estimate future prognosis when evaluating whether a rate of glaucoma progression can be clinically relevant.