In addition, neurodegeneration of dopaminergic amacrine cells has been linked with alpha-synuclein overexpression in the eyes of patients with Parkinson’s disease and precedes the development of clinical signs.45 Local cytoplasmic inclusions and dopaminergic loss confirm the presence of neurodegenerative changes in the retina and potentially reflect similar changes in the central nervous system.91 This evidence concerns the gene SNCA and Parkinson disease.