The avascular zone and neuronal remodeling of the fovea in Parkinson disease

Inner foveal thinning and intracellular alpha-synuclein were demonstrated in the retina in Parkinson disease. While pathognomonic alpha-synuclein is associated with embryonic dopaminergic (DA) neurons, postmortem studies in the nervous system and retina show prominent effect also in non-DA neurons. We evaluated foveal capillaries and foveal thickness in 23 Parkinson disease subjects and 13 healthy controls using retinal fluorescein angiography and optical coherence tomography. The size of the foveal avascular zone inversely correlates with foveal thinning. Foveal thinning highly correlates with motor impairment and also disease duration. Quantifying capillary and neuronal remodeling could serve as biological markers.