Parkinson's disease (PD) is one of predominant degenerative diseases of the central nervous systemCentral nervous system (CNS), mainly caused by the degeneration of dopaminergic neurons, with the main clinical manifestations being bradykinesia, rest tremor and rigidity. RetinaRetina has been regarded as the window towards CNS and contains dopaminergic neurons. Screening, predicting, and assessing the onset, prognosis, and outcome of PD via retinaRetina has been a widespread interest in ophthalmology and neuroscience. In recent years, optical coherence tomography (OCTOptical Coherence Tomography (OCT)) of the retinaRetina, a noninvasive, convenient, and inexpensive retinal imagingImaging technique, has gained broad attention. The significance of OCTOptical Coherence Tomography (OCT) in PD has also been widely studied. In this chapter, we first review the histologic, physiologic, and pathologic associations of the retinaRetina and PD, followed by a glance of OCTOptical Coherence Tomography (OCT) technical features and recent OCTOptical Coherence Tomography (OCT) imagingImaging advances, then a demonstration of OCTOptical Coherence Tomography (OCT)-based imagingImaging markers in PD, followed by a summary of the clinical associations of these markers and PD, then a summarization of OCTAOCT angiography (OCTA) in PD, and finally a brief demonstration of the functional-morphological retinal changes in PD patients. We believe that OCTOptical Coherence Tomography (OCT) has a special significance for screening, diagnosisDiagnosis, and efficacy prediction of PD. However, these results need to be examined in large-scale population-based cohorts, and advances in novel image analysisImage analysis technologies, such as artificial intelligence, will lend fresh impetus into this field.