Molecular Mechanisms and Clinical Manifestations of Catecholamine Dysfunction in the Eye in Parkinson's Disease As a Basis for Developing Early Diagnosis.

This review provides information on the non-motor peripheral manifestations of Parkinson's disease (PD) associated with a pathology of the visual analyzer and the auxiliary apparatus of the eye. The relationship between neurodegenerative processes that take place in the brain and in the eye opens new prospects to use preventive ophthalmologic examination to diagnose PD long before the characteristic motor symptoms appear. This will encourage the use of neuroprotective therapy, which stops, or at least slows down, neuronal death, instead of the current replacement therapy with dopamine agonists. An important result of an eye examination of patients with PD may be a non-invasive identification of new peripheral biomarkers manifesting themselves as changes in the composition of the lacrimal fluid.