Vision-related quality of life.

Since the World Health Organization (WHO) stated that “health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity,” the impact of a disease or treatment on the patient’s life has become increasingly measured using assessments of well-being or quality of life (QoL) in addition to more traditional clinical measures. Indeed, health-related QoL (HR-QoL) measurements are now a standard part of clinical trials of health interventions. Although there is some debate about the precise definition of HR-QoL, the content of HR-QoL instruments typically includes an assessment of the ability to perform activities of daily living, interactions with other people, emotional well-being, and independence. Other dimensions have also been measured. Because of the breadth of HR-QoL and its patient-centered nature, it has been measured using questionnaires (called instruments in the research literature), which can be efficient tools for gathering large amounts of data quickly. A prime example of the importance of these instruments in measuring outcome is the evaluation of the usefulness of second eye cataract surgery. In the 1990s, several U.S. insurance companies and UK health authorities suggested that cataract surgery for the second eye was not necessary based on the relatively minor benefits provided in terms of binocular visual acuity. However, several studies used self-reported questionnaire data to provide evidence that patients experienced substantial improvements in performing everyday activities that are dependent on vision as well as in symptoms and QoL. The value of the surgery is no longer questioned. Most recently, there are concerns that many older adults with low vision that have cataract as a secondary diagnosis, are not considered for surgery, in large part because studies have demonstrated only limited improvements in VA. Yet few studies have examined the impact of such surgery on patient QoL, independence, and community participation. Included in this special issue is a report that highlights the major improvements in VR-QoL that cataract surgery can make to patients with both cataract and age-related macular degeneration. These examples highlight the value of QoL instruments in demonstrating the range of benefits possible from cataract surgery.