Review of the visual system in Parkinson's disease.

In an era when the prevalence of Parkinson's disease (PD) is increasing because our population is aging, eye care professionals need to become aware of the visual changes experienced by PD patients. This paper reviews the visual pathophysiology of PD and the results of the lack of dopamine on the retina and visual cortex. It also discusses the impact of PD on the oculomotor system and the visual sensory pathways with the consequent effects on reading, balance, and driving abilities of PD patients. Further research on the visual system and PD may provide improved means for early diagnostic testing as well as the possibility of vision rehabilitation for treatment of visual performance impairments.