Retinal Deposits of Phosphorylated Alpha-Synuclein: A Biomarker for Parkinson’s Disease?
Analysis of retinas from 19 autopsied subjects, 9 with Parkinson’s disease (PD), and 4 with incidental Lewy body disease, showed accumulation of phosphorylated α‐synuclein (AS) that was not seen in any of 6 control subjects (Movement Disorders. 2018:published online May 8).
Using antibodies to phosphorylated AS, researchers Isabel Ortuno-Lizaran, Thomas G. Beach, Geidy E. Serrano, and others found deposits of phosphorylated AS in all areas of retinal ganglion cells. Some of these deposits resembled the known Lewy body and Lewy neurite pathology of PD. Neuropathology of the brains from patients with PD or incidental Lewy body disease also showed Lewy‐type synucleinopathy that significantly correlated not only with the AS density in the retina, but also with the patients known clinical symptoms that had be measured with the Unified Parkinson's Disease Pathology Stage and the motor Unified Parkinson’s Disease Rating Scale.
The authors of the study suggest that phosphorylated AS in the retina accumulates in parallel with accumulation in the brain, including in early stages preceding development of clinical signs of parkinsonism or dementia. They propose that the retina may provide an in vivo indicator of brain pathology severity, that detection of phosphorylated AS in the retina could aid diagnosis and monitoring of disease progression.