Diabetic retinopathy (DR), one of the microvascular complications of diabetes mellitus, is an important blinding disease in people over 50 years old.Various optical methods are used to detect retinal angiopathy and evaluate the progress of DR.However, there are also changes in microstructure and function of visual pathways in DR patients, which may occur earlier than retinal angiopathy.Functional magnetic resonance imaging (fMRI) can detect ocular blood flow biological parameters and visual pathway function, and has the advantages of noninvasive procedure, precise positioning and high repeatability.fMRI includes perfusion-weighted MRI (PWI), voxel-based morphometry (VBM), magnetic resonance spectrum (MRS), diffusion-weighted MRI (DWI), and blood oxygen level-dependent fMRI (BOLD-fMRI). PWI can be used to investigate the early retinopathy of DR, and manganese-enhanced MRI can be used to explore the changes of retina and choroid activity in the early stage of DR.Arterial spin labeling can be used to detect ocular blood flow.VBM is able to detect changes in gray matter.MRS can be used to detect biochemical reactions of the cerebrum by calculating the peak value of metabolites.DWI reflects brain injury by apparent diffusion coefficients.BOLD-fMRI is used to detect changes in the brain neuron activity and brain network function of DR.In this paper, the role of fMRI in the functional evaluation of visual pathways in DR was reviewed.

Diabetic retinopathy; Functional magnetic resonance imaging; Review