according to the results of a multicenter, cross-sectional cohort study.
“Ophthalmologic symptoms are underreported by patients with Parkinson’s disease and often overlooked by their treating physicians,” noted the investigators, who were led by Carlijn D.J.M. Borm, MD, Parkinson Centre Nijmegen (the Netherlands), Department of Neurology, Donders Institute for Brain, Cognition and Behaviour at Radboud University Medical Centre. “Importantly, intact vision is especially vital for patients with Parkinson’s disease to compensate (through visual guidance) for their common loss of motor automaticity that is caused by basal ganglia dysfunction.”
The investigators studied 848 patients with Parkinson’s disease in the Netherlands and Austria who were recruited by e-mail or in outpatient clinics and 250 age-matched healthy controls drawn from partners and acquaintances, comparing the groups on symptoms assessed with the Visual Impairment in Parkinson’s Disease Questionnaire (VIPD-Q).
Results reported in Neurology showed that 82% of patients with Parkinson’s disease reported at least one ophthalmologic symptom, compared with 48% of age-matched healthy controls (P < .001). Symptoms related to the ocular surface – blurry near vision, a burning or gritty sensation, mucus or particles, and watering of the eyes – were the most common.
Moreover, 68% of patients reported having ophthalmologic symptoms that interfered with daily activities, compared with 35% of healthy controls (P < .001).
The study’s findings suggest “that either Parkinson’s disease itself or its treatment has an effect on ophthalmologic functions beyond the normal aging process,” Dr. Borm and coinvestigators wrote. “The high prevalence of ophthalmologic symptoms and their effect on daily life is striking, and emphasizes the need to address this subject in both research and clinical practice.”
“Patients who report ophthalmologic symptoms need a referral for further evaluation. For those patients who do not volunteer problems themselves, a screening questionnaire such as the VIPD-Q may help with identifying ophthalmologic symptoms in patients with Parkinson’s disease that might otherwise be missed, thereby enabling timely referral and treatment,” they noted.
Study details
The study participants were 70 years old, on average, and the patients with Parkinson’s disease had had the disease for a median duration of 7 years. Compared with the healthy control group, the patient group more often reported that they used visual aids (95% vs. 88%; P = .001) and had visited an ophthalmologist (35% vs. 19%; P < .001). The median score on the VIPD-Q, out of a possible 51 points, was 10 among the patients with Parkinson’s disease, compared with 2 among the healthy controls (P < .001).
Patients most commonly reported symptoms related to the ocular surface (63% vs. 24% among controls; P < .001). But they also often reported symptoms in the intraocular domain (54% vs. 25%; P < .001), the oculomotor domain (44% vs. 10%; P < .001), and the optic nerve domain (44% vs. 19%; P < .001). Fully 22% of the patients reported visual hallucinations, compared with just 2% of the healthy controls (P < .001).
As VIPD-Q score increased, so did the likelihood of falls (odds ratio, 1.043; P < .001). In addition, patients with Parkinson’s disease more often reported that ophthalmologic symptoms had a moderate or severe impact on their quality of life (53% vs. 16%; P < .001).
Dr. Borm disclosed no relevant conflicts of interest. The study was funded by the Stichting Parkinson Fonds.