Ocular features of patients with Parkinson’s disease examined at a Neuro-Optometry Clinic in a tertiary eye care center

PURPOSE: To report the ocular features of patients with PD who presented with visual complaints to a tertiary eye care center. METHODS: This was a retrospective study carried out between January 2015 and March 2020 at the Neuro-Optometry clinic of a tertiary eye care center in Southern India. All PD patients with ocular complaints examined by the neuro- ophthalmologists were referred to Neuro-Optometry Clinic for detailed evaluation. Patients with other neurodegenerative disorders, brain injury, and other causes of vision loss or extraocular motility disorders were excluded. RESULTS: A total of 43 patients (7 females, 36 males) between 50 and 86 years of age (mean: 70 ± 8.9 years) with a mean duration of PD of 4.5 ± 4.5 years were studied. Decreased vision associated with reading difficulty (40%) was common in PD patients. In terms of gaze restriction, vertical gaze involvement (35%) was more than horizontal involvement (7%). Convergence insufficiency (CI) was the most common binocular vision dysfunction (30%), followed by CI with oculomotor dysfunction (14%) and vertical gaze palsy (18%). Ground prisms were recommended for 26 patients (61%) and home vision therapy for 5 patients (12%) as corrective measures. CONCLUSION: Binocular vision dysfunction is highly prevalent among PD patients. This could potentially contribute to the reading difficulties and double vision encountered by these patients. Assessment of binocular vision and oculomotor parameters thus becomes important to understand and manage the reading difficulties in patients with PD.