Double vision in Parkinson's Disease: a systematic review

Area of Science:

• Neurology
• Ophthalmology
• Movement Disorders

Background:

• Diplopia (double vision) affects 10-30% of individuals with Parkinson's disease (PD).
• Symptoms can range from intermittent, situational double vision to constant visual disturbances.
• Understanding diplopia in PD is crucial for improving patient quality of life and safety.

Purpose of the Study:

• To review current knowledge on the frequency, causes, diagnosis, pathophysiology, and treatment of diplopia in Parkinson's disease.
• To supplement the review with insights from two case studies.
• To highlight the impact of diplopia on the quality of life for PD patients.

Main Methods:

• Systematic electronic literature search conducted in May 2020 using PubMed, Scopus, Embase, and Web of Science.
• Search terms included 'Parkinson's Disease' and 'diplopia'.
• Inclusion of five relevant articles and two case studies.

Main Results:

• Diplopia in PD is typically intermittent and binocular, with single object diplopia being most common.
• Identified risk factors include older age, longer disease duration, disease severity, cognitive decline, visual hallucinations, and higher levodopa equivalent dose.
• Diplopia significantly impacts quality of life and may be associated with comorbidities like myasthenia gravis and vascular disease.

Conclusions:

• Diplopia is a common yet understudied complication of Parkinson's disease.
• It significantly affects patient quality of life and safety.
• Acute diplopia onset necessitates exclusion of other conditions, and tailored interventions are essential for improved patient outcomes.