AIM: To evaluate the changes in macular morphology and function after a single intravitreal injection of aflibercept in diabetic macular edema (DME) using optical coherence tomography angiography (OCTA) and MP-3 microperimetry. METHODS: Twenty-eight patients (42 eyes) diagnosed with DME were treated with intravitreal injection of aflibercept. The changes in best corrected visual acuity (BCVA), central retinal thickness (CRT), foveal avascular zone (FAZ) area, vessel density of superficial retinal capillary plexus (SVD), vessel density of deep retinal capillary plexus (DVD), mean light sensitivity (MLS), 2° fixation rate (P1), 4° fixation rate (P2), and other indicators 1mo after treatment were compared; of these, BCVA was converted into logarithm of the minimum angle of resolution (logMAR), and the correlation among the factors was analyzed. RESULTS: After treatment, logMAR BCVA was 0.47±0.24, which was significantly better than that before treatment (0.63±0.28, P