“The idea that visual symptoms may be associated with Parkinson’s disease is not new, but this is the first time it has been reported at the population level,” he told Medscape Medical News Ali Hamedani of the University of Pennsylvania in Philadelphia, lead author of a study published in European Journal of Neurology.
Analyzing data obtained through a large survey, U.S. researchers found that visual dysfunction is significantly more common in individuals with Parkinson’s disease than in the general adult population. However, this is a generally overlooked and untreated factor, even though it worsens the already compromised quality of life of these patients.
The survey was conducted on more than 150,000 individuals and calculated that people diagnosed with Parkinson’s disease were more than twice as likely to suffer from vision impairment in both near and far vision as the general population.
Vision problems had been repeatedly reported by the patients themselves, their caregivers and attending physicians. So, the suspicion was evidently already there, but the new study provides a confirmation supported by a large-scale survey, and the large number of data allows a statistical correlation to be documented that otherwise would not have been so stringent.
With colleague Allison Willis, Hamedani analyzed data of adults aged 50 years and older provided by the Survey of Health, Aging and Retirement in Europe. (SHARE), a multinational population health survey of people living in one of 27 European countries and Israel.
Although the risk of impaired distance vision was 2.55 higher (and near vision 2.07), people with Parkinson’s reported this difficulty to an ophthalmologist less often, so that the condition remained untreated in many cases.
The study authors report that there have been some suggestions of a subtle change in color vision in the years before Parkinson’s diagnosis, but it is unlikely that patients themselves will notice. “It could probably be found out if screening was done, but it is too early for any recommendations on that,” Hamedani said. Instead, the researcher suggested that physicians examine visual function in already diagnosed patients, although the nature and significance of these symptoms still appear unclear: we do not know whether the mechanism is the result of Parkinson’s-associated changes directly in the eyes or at the brain level.
Source:
Hamedani AG, Willis AW. Self-reported visual dysfunction in Parkinson disease: the Survey of Health, Ageing and Retirement in Europe. European Journal of Neurology 2019, 0: 1-6.
