A new study finds that measuring stress in patients with age-related macular degeneration (AMD) can help assess the disease’s life impact and progression.
AMD is an eye disease that affects the macula, the part of the eye responsible for seeing fine details and focusing straight ahead. It is the leading cause of vision loss among older adults in the United States and is often associated with psychological stress.
According to the findings, published in the journal Optometry and Vision Science, a simple stress rating scale called the Perceived Stress Scale (PSS) is a valid and useful way to evaluate the connection between stress and progressive vision loss from AMD.
“Because AMD is an inflammatory disease, we are studying the link between inflammation, stress, and AMD treatment outcomes,” said Bradley E. Dougherty, OD, Ph.D., of the Ohio State University College of Optometry. “In the end, we hope to better understand how general well-being influences disease outcomes.”
AMD patients with vision loss experience high levels of stress, anxiety, and depression. Less is known about the relationship between the stress that AMD patients experience and the severity of their disease — for example, whether stress can cause AMD to worsen or not.
The PSS is a well-established stress rating scale that can predict objective biological markers of stress, as well as the risk of stress-related diseases. In prior research, the PSS has been shown to be predictive of general markers of inflammation, including C-reactive proteins. In the new study, the research team extended the use of this survey to determine how well it measures perceived stress in patients with vision loss due to AMD.
For the study, 137 AMD patients (average age 82) completed the 10-question PSS. About half of the patients filled out the stress questionnaire on a day when they received injections of anti-VEGF antibodies — a relatively new treatment that can slow the progression of the more advanced “wet” form of AMD. Wet AMD affects about 10-15 percent of AMD patients but accounts for about 90 percent of the severe vision loss associated with the disease.
Nine of the 10 questions typically used with the PSS performed well with the patient group studied. These nine items were also able to separate between patients with higher versus lower levels of perceived stress. For some PSS items, responses differed according to patient age and visual acuity level.
“A psychometrically sound, easy-to-administer questionnaire such as the PSS is important for use with patients with AMD, given the evidence for increased rates of psychological symptoms in the population,” writes Dougherty and coauthors.
The researchers note that stress-reduction approaches, such as mindfulness interventions, have led to improved outcomes in patients with various health conditions.
Dougherty and colleagues also note that stress may be associated with increased inflammation and that AMD is an inflammatory disease — raising the possibility that stress may contribute to disease progression. Future research using repeated assessments with the PSS and measurement of inflammatory markers might help determine how perceived stress levels affect the risk of AMD progression and deteriorating vision.
Source: Wolters Kluwer Health