American adults who lose the eyesight they need to accomplish everyday tasks are almost twice as likely to be depressed as other adults, an analysis of data from a large federal health survey has revealed.
Xinzhi Zhang, MD, PhD, from the Division of Data Management and Scientific Reporting, National Institute on Minority Health and Health Disparities, National Institutes of Health, Bethesda, Maryland, and colleagues report their results in an article published online March 7 in JAMA Ophthalmology.
To assess the relationship between vision and depression, the authors used data from the 2005-2008 National Health and Nutrition Examination Survey (NHANES), which included 10,480 adults. This recurring, nationally representative survey nation's health is sponsored by the Centers for Disease Control and Prevention (CDC).
NHANES asked participants about their ability to perform 6 vision-related functional tasks: reading a newspaper; close-up tasks; going down steps, stairs, or curbs in dim light or at night; noticing objects off to the side of the visual field when walking; finding items on a crowded shelf; and driving in familiar places during daytime hours. Depression was assessed with a 9-question screening test, the Patient Health Questionnaire, which is a shorter, well-validated version of the Primary Care Evaluation of Mental Disorders.
The estimated weighted (crude) prevalence of depression in adults aged 20 years or older with self-reported visual function loss was 11.3% (95% confidence interval [CI], 9.7% - 13.2%) compared with 4.8% in adults without any self-reported functional impairment (95% CI, 4.0% - 5.7%).
"People with any kind of visual function loss are more likely than those with none to report depression, especially in key activities of daily living such as driving. Even after considering possible confounding factors, adults with visual function loss are at least 90% more likely to have depression than those without visual function loss," the researchers write.
When the investigators adjusted the data for 18 other characteristics related to depression, the prevalence of depression and the odds ratios fell slightly, but the proportions did not change. The team adjusted for age, sex, race/ethnicity, socioeconomic factors, and unhealthy behaviors (eg, smoking), as well as chronic diseases.
The odds ratio for depression was 1.9 (95% CI, 1.6 - 2.3) among adults with self-reported loss of visual functioning relative to those without functional impairment, after adjusting for other factors.
The investigators also found that
Between 11.3% and 25.0% of the people who reported difficulty performing a single visual-function task had depression, depending on the task, compared with 5.3% to 6.1% of the people who had no difficulty with functional vision.
The highest prevalence of depression, 25.0%, was in people who reported having difficulty with daytime driving.
The prevalence and severity of the depression increased as the number of visual function problems grew (P < .01 for comparison).
However, depression risk was higher in adults who reported functional impairment than it was in participants who had frank reductions in visual acuity that were uncorrectable.
In an interview with Medscape Medical News, William Trattler, MD, a Miami cataract and refractive surgeon, said he found it interesting to know that patients who have conditions such as age-related macular degeneration who accept their vision loss are not more depressed.
"We know that Snellen acuity is performed in optimal situations, with a high-contrast target. However, functional vision is harder to assess. While a patient may have good visual acuity, they may not have the ability to function well in real-world situations, like driving a car," he said.
Study coauthor Jinan B. Saaddine, MD, MPH, is the team leader coordinating a CDC vision health initiative to reduce visual impairment in the United States. Prevalence research such as this study is needed to establish a visual health surveillance system to monitor progress, Dr. Saaddine said. However, the study also broke new ground, she added.
"The uniqueness of this study is that it was done in a national sample. NHANES samples people nationally and from all adult age groups. We were not just looking at [the] Medicare population," Dr. Saaddine said in an interview with Medscape Medical News.
Advocates for people with vision loss say that adults with low vision can thrive with the help of low-vision specialist teachers. However, physicians must know to refer them, Charlene Cook, a teacher for the Oregon Commission for the Blind in Portland, told Medscape Medical News.
Clients who consult her typically arrive upset, anxious, and terrified of a life without eyesight, she said. "They don't really know what blind people do, how blind people live. You need to teach people who are losing their vision how to do everything. You have to learn to eat again, to travel again."
Even with help, money can be a barrier, she said. Medicare does not pay for assistive devices like screen readers, and state commissions for the blind often will only handle vocational rehabilitation cases.
This study was supported by the National Center for Health Statistics of the CDC. Funding for the NHANES retinal component was provided by the Division of Diabetes Translation of the CDC. Funding for the vision component was provided by the National Eye Institute/National Institutes of Health. The authors, Dr. Saaddine, and Cook have disclosed no relevant financial relationships. Dr. Trattler is a consultant for several ophthalmic companies, including Abbott Medical Optics, Alcon, Allergan, and Bausch + Lomb.
JAMA Ophthalmol. Published online March 7, 2013. Full text
Medscape Medical News © 2013 WebMD, LLC
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Cite this: Vision Loss Linked to Depression - Medscape - Mar 13, 2013.