Undetected ophthalmological disorders in Parkinson’s disease

BACKGROUND: Ophthalmological disorders are common and frequently disabling for people with Parkinson’s disease (PD). However, details on the prevalence, severity and impact of ophthalmological disorders thus far lacking. We aimed to identify PD patients with undetected ophthalmological disorders in a large cross-sectional, observational study. METHODS: We previously delivered a screening questionnaire to detect ophthalmological symptoms (Visual impairment in PD questionnaire; VIPD-Q) to 848 patients. Here, we report on a subgroup of 102 patients who received complete ophthalmological assessment aimed at identifying clinically relevant ophthalmological diseases, which were classified as either vison-threatening or not. Impact on daily life functioning was measured using the visual functioning-25 questionnaire (VFQ-25) and fall frequency. RESULTS: Almost all patients (92%) had one or more clinically relevant ophthalmological disorders. Of those, 77% had a potentially vision-threatening disease, while 34% had a potentially treatable ophthalmological disease which impacted on quality of life. The most prevalent ophthalmological disorders were dry eyes (86%), ocular misalignment (50%) and convergence insufficiency (41%). We found a weak but significant association between clinically relevant ophthalmological diseases and both fall frequency (R(2) = 0.15, p = 0.037) and VFQ-25 score (R(2) = 0.15, p = 0.02). The VIPD-Q could not correctly identify patients with relevant ophthalmological disorders. CONCLUSIONS: Surprisingly, in our study sample, many participants manifested previously undetected ophthalmological diseases, most of which threatened vision, impacted on daily life functioning and were amenable to treatment. Screening for these ophthalmological disorders using a questionnaire asking about symptoms seems insufficient. Instead, episodic ophthalmological assessments should be considered for PD patients, aiming to identify vision-threatening yet treatable diseases. TRIAL REGISTRATION: Dutch Trial Registration, NL7421. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00415-022-11014-0.