The role of ocular computed tomography to detect cognitive changes in Parkinson's disease

Parkinson’s disease (PD) is characterized by a number of symptoms, one of which is cognitive impairment, which, as the disease progresses, becomes more severe and of greater risk. Changes in anatomy and function of the retina have been discovered in patients with PD. The macular retinal thickness, macular volume, and average retinal nerve fiber layer (RNFL) thickness were decreased were concomitant in cognitive decline of PD. Optical coherence tomography (OCT) measurements of RNFL have been proposed as biomarkers of axonal damage in PD. The aim of this review is to discuss the cognitive changes occurring in PD, the challenge associated assessment and how OCT overcome this issue.