Background:
Age-related macular degeneration (AMD) is the leading cause of severe vision loss in older adults. The prevalence of AMD is increasing and, in a cohort of Medicare beneficiaries, it increased from 5.0% to 27.1% from 1991 to 1997. For advanced disease, the age-specific AMD prevalence increased from 0.1% in 43-54 year olds to 7.8% of those over 75 years. As the population ages, the prevalence of AMD will increase --by 50% in the next 20 years-- and will impair many older persons' ability to live independently, socialize, read, and drive. These losses will increase the risk of depression, falls, hip fractures and institutionalization.
Because no current treatment restores vision, AMD-related disability will become a major public health problem. The U.S. now spends more than $30 billion annually on care for people with severe vision impairment; for vision-related hip fractures alone we spend $2.2 billion each year. Unfortunately, our fragmented health care system fails to provide comprehensive vision care to older persons. Finding ways to improve vision function is clearly important. One way is to enhance problem-solving skills. This could preserve independence for patients, reduce burden on caregivers, and improve the quality of life for both. Eye care professionals support but often cannot provide this treatment because they lack the resources, time, and ability to implement problem solving treatment (PST). As a result, excess disability and associated problems persist in many patients.
This study aims to determine whether enhancing problem-solving skills improves vision function and reduces disability. If successful, PST may well generalize to other chronic, disabling disorders. AMD provides an ideal model to test this approach because it is common, affects men and women equally, is quantifiable in terms of severity, and produces disability within a short time period. Patients with other causes of severe vision loss (e.g. diabetic retinopathy, glaucoma) face many of the same problems. If effective, PST's beneficial effects may apply to these disorders as well.
Impaired vision function leads to limitations in preparing meals, managing medications, mobility, and increases the likelihood of falls and hip fractures. Although there is no standard approach to measure vision function, valid and reliable self-report scales exist [e.g. Activities of Daily Vision Scale, VF-14, and the National Eye Institute-Visual Functioning Questionnaire (NEI-VFQ)]. None of the existing vision function instruments explicitly assess a task's value in a patient's life or whether important personal goals are achieved in response to treatment. A model for classifying valued vision-related activities has been developed: the Activity Breakdown Structure and its associated Activity Inventory (AI) measurement tool. We plan to use the AI to derive our primary outcome measure (i.e. targeted vision function). The targeted vision function measure is composed of (up to) 4 vision-related goals derived from the Activities Inventory.
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Description:
The primary objective of this randomized clinical trial is to compare vision function at 3 months in subjects with AMD assigned to receive PST with those assigned to receive Supportive Therapy (ST). ST is a common placebo treatment used in psychotherapy trials. Vision function will be assessed using targeted vision function, a novel approach in which subjects rate the difficulty of 1 to 4 goals that are important for them to accomplish, yet difficult to achieve. The interventions will take place weekly for 6 weeks in subjects’ homes. Baseline and outcome (3 and 6 months) assessments will be conducted by an RN and will also take place in subjects' homes.
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Health
