Vision Problems Common in Older Parkinson’s Patients in US, Study Finds

Problems with vision are more common in older people with Parkinson’s disease than in others of a similar age, and are linked with poorer health outcomes, a study based on U.S. Medicare records found.

Fewer than 60% of the more than 285,000 Parkinson’s patients whose data were analyzed, however, had annual eye exams.

The study, “Visual Impairment Is More Common in Parkinson’s Disease and Is a Risk Factor for Poor Health Outcomes,” was published in Movement Disorders.

Difficulties with vision at older ages — Medicare beneficiaries in the U.S. are overwhelmingly people age 65 or older — are associated with a poorer quality of life, including a greater risk of falls, depression, anxiety, and dementia, the study noted.

With vision problems increasingly recognized as a nonmotor symptom of Parkinson’s, researchers at the University of Pennsylvania investigated Medicare claims data from 2010–14, looking at the prevalence of these problems and outcomes in this patient group.

Specifically, they sought to determine the prevalence of moderate to severe visual impairment in Parkinson’s patients, and how poorer vision related to disease outcomes. They also explored patterns of eye examinations given patients.

Because most causes of visual impairment are either preventable or treatable, they wrote, findings could lead to better healthcare approaches in patients at greater risk for diminished vision.

Researchers first examined 26.21 million unique Medicare beneficiaries in 2014. Of them, 287,010 (1.1%) had a diagnosis of Parkinson’s, and 187,572 (0.72%) had a diagnosis of moderate to severe visual impairment.

Such impairment was significantly more common in the Parkinson’s group (1.67%) than the general older adult population (0.71%), data from 2010–14 showed. But in both groups, vision problems were especially common among those of racial and ethnic minority backgrounds (Blacks and Hispanics), as well as in the more elderly, women, and those with diabetes and hypertension.

After adjusting for these variables, visual impairments remained significantly more common, by 60%, in the Parkinson’s population.

Factors affecting health outcomes, like demographics, tobacco use, obesity, and diabetes, were also adjusted. Data then showed that moderate to severe visual impairment was significantly associated with depression, anxiety, and dementia in people with Parkinson’s.

Over the years of follow-up, 54.6% to 56% of these patients underwent at least one eye exam, with examination rates higher for older patients, whites, those living in metropolitan areas, and people under a neurologist’s care. Male patients and those with dementia were associated with lower rates of eye exams.

Across this patient group, 37.2% had diabetes (which can cause eye problems), 36.3% had cataracts, 18.9% had age-related macular degeneration, and 14.9% had glaucoma. Having such a disorder did not lead to higher eye examination rates, but those rates were significantly higher among patients with diabetes or any form of eye disease.

In fact, only 54% of Parkinson’s patients with visual impairment had at least one annual eye exam. But this rate rose to 78.3% for those with age-related macular degeneration, 80.5% for those with diabetic retinopathy, and 84% for people with cataracts.

The highest eye examination rate was among patients with glaucoma; 91.6% had at least one eye exam each year.

These findings show that “visual impairment is more common in PD [Parkinson’s disease] than the general population,” the researchers wrote. They attribute this to possible shared molecular mechanisms between Parkinson’s and eye diseases, lesser access to ophthalmic care, or to difficulties applying certain eye treatments. Drops, for instance, can be challenging for people with a disease that causes tremors and affects dexterity.

Still, “because more than half of all‐cause visual impairment in older adults is preventable or treatable, the identification of [Parkinson’s] as a risk factor for eye‐related visual impairment presents a unique opportunity to target early detection and treatment programs for these patients to prevent future visual impairment,” the researchers added.