Diabetic macular edema(DME)is a complication of diabetic retinopathy(DR), and is also the main cause of vision loss and blindness in DR patients. Optical coherence tomography(OCT)and optical coherence tomography angiography(OCTA)serve as the principal methods for the non-invasive assessment of microstructural and microvascular pathological changes in the retina. They are widely-used methods for detecting and evaluating DME. As OCT and OCTA technologies advance, various parameters have assumed the role of biomarkers, such as central subfield thickness(CST), cube average thickness(CAT), cube volume(CV), disorganization of retinal inner layers(DRIL), hyperreflective foci(HRF)and subfoveal neuroretinal detachment(SND). OCT and OCTA are widely used in clinical practice. OCT can visually show the layer changes and subtle structures of the retina and choroid in the macular area, while OCTA is more often used to detect microvascular changes. In this article, the role of OCT and OCTA-related biomarkers in prognosis and monitoring in DME is described, while the biomarkers visible in the test results can provide new ideas for monitoring and treatment strategies in DME, and provide new insights into the pathogenesis of DR and DME.