Annals of Long Term Care

The leading cause of vision impairment and blindness in the United States is age-related eye disease, including age-related macular degeneration, cataract, diabetic retinopathy, and glaucoma. There are many medication safety issues associated with vision loss. Access to prescription information, including medication labels and usage instructions, is essential for the correct taking of medication. However, many people with vision loss are unable to access important instructions for use and safety information; determine the color, shape, and markings distinguishing a medication; or see markings on measuring or testing devices. Most older people who lose their vision due to age-related eye disease are not aware of services that can help them cope with vision loss, or techniques and devices that can make medication-taking and activities of daily living easier and safer. Clinicians can direct these patients to resources designed to help enhance patient function and medication safety. (Annals of Long-Term Care: Clinical Care and Aging 2009;17[6]:17-22)

Introduction

According to the 2006 National Health Interview Survey (NHIS), of the more than 20 million Americans who reported vision loss, 6.2 million of them are age 65 years and older.1 In addition, there are approximately 9 million Americans age 45-64 who reported that they have trouble seeing, even with glasses or contacts, or that they are blind or unable to see at all.1 As the millions of baby boomers continue to age, the number of older persons with vision loss will continue to grow substantially.

The leading cause of vision impairment and blindness in the United States is age-related eye disease, including age-related macular degeneration (AMD), cataract, diabetic retinopathy, and glaucoma.2 The number of Americans with age-related eye disease and the vision impairment that results is expected to double within the next three decades.2 In addition to age-related eye diseases, physiologic changes in vision that occur with age—loss of near focus, reduced contrast sensitivity, and visual field impairment—contribute to vision impairment.

The Aging Eye

The most common age-related visual change is a decrease in the ability of the eyes to focus for close-up work (presbyopia). Other visual changes in the aging eye include a need for increased lighting, impaired color discrimination, and decreased contrast sensitivity (difficulty discerning an object against a similarly colored background). Most older adults need three to four times more light (particularly task lighting) than they previously did to perform certain types of everyday tasks. However, vision loss is not a normal part of aging.

When vision changes cannot be fully corrected to the normal range with ordinary eyeglasses, contact lenses, medication, or surgery, the result is permanently impaired vision, or low vision. Low vision refers to a range of vision capabilities and is common in older adults.

Ocular changes caused by aging are further compounded by eye disease. The four most prevalent eye conditions or diseases are diabetic retinopathy, glaucoma, cataract, and AMD. Increased age is a risk factor for cataract, diabetic retinopathy, and macular degeneration. Persons with diabetes also have a greater incidence of cataract and glaucoma. Consequently, many older adults have multiple, overlapping eye conditions.

A complete review of the pathophysiology, diagnosis, and treatment of age-related eye disease is beyond the scope of this article.

Diabetic Retinopathy

Diabetic retinopathy occurs in 4.4 million Americans age 40 years and older,2 or approximately 25% of the 17.9 million Americans diagnosed with diabetes.3 It can be present even though no subjective signs of vision loss are experienced by the individual having the condition.