Ophthalmologic features of Parkinson's disease

Abstract

Patients with Parkinson's disease (PD) commonly complain of impaired visual function and difficulty reading, despite normal visual acuity. Visual problems are particularly important in this population of patients with impaired ambulation and driving safety issues. Although previous studies have evaluated contrast sensitivity, color vision, visuospatial processing, visual hallucinations, and ocular movements, none has systematically evaluated the ocular complaints and ocular findings of PD patients. Thirty patients with early untreated PD and 31 control subjects without neurologic or known ocular diseases were ophthalmologically evaluated for the frequency of visual complaints, dry eyes, blepharitis, visual hallucinations, reduced blink rate, blepharospasm, and convergence insufficiency. Ocular complaints suggesting ocular surface irritation, altered tear film, visual hallucinations, blepharospasm, decreased blink rate, and decreased convergence amplitudes were more common in PD patients than in control subjects. These findings likely account for many of the visual difficulties commonly encountered by PD patients and are directly secondary to PD and not to side-effects of drugs used to treat PD. These ocular abnormalities frequently respond to treatment. A list of practical advices regarding the ocular evaluation of PD patients is provided at the end of the article.—authors’ abstract