ObjectiveTo observe and analyze the correlation between the level of intracocular fluid cytokines and the changes of macular microvascular structure in patients with diabetic macular edema (DME). MethodsA prospective clinical study. From December 2022 to June 2024, 20 patients with 25 eyes of DME diagnosed by Department of Ophthalmology of Linyi People's Hospital were included in the study. Among them, 14 males had 17 eyes and 6 females had 8 eyes. Age was (55.08±10.34) years. Optical coherence tomography (OCT) and OCT angiography (OCTA) were used to scan the macular region at a range of 6 mm×6 mm. Central retinal thickness (CRT), blood flow density of superficial retinal capillary plexus (SCP) and area of avascular fovea of macula (FAZ) were measured. The anterior aqueous humor was extracted before the first intravitreal injection of anti-vascular endothelial growth factor (VEGF), the concentrations of interleukin (IL-6), IL-8, VEGF, vascular cell adhesion molecule (VCAM), placental growth factor (PLGF) and monocyte chemotactic protein-L (MCP-1) were detected. The correlation between macular microvascular structure and aqueous humor cytokines was analyzed by Spearman correlation analysis. ResultsThe CRT of the affected eyes was (617.40±167.64) μm, the SCP flow density was (39.56±1.55)%, and the FAZ area was (0.46±0.13) mm². The concentrations of IL-6, IL-8, VEGF, VCAM, PLGF and MCP-1 in aqueous humor were (301.36±690.52), (29.15±20.56), (71.37±29.32) and (5 621.22±7 241.06), (72.40±13.43), (464.07±163.26) pg/ml, respectively. Correlation analysis showed that there was a significant positive correlation between CRT and the concentrations of aqueous cytokines VEGF and PLGF (r=0.460, 0.462, P＜0.05). FAZ area was positively correlated with VEGF and MCP-1 concentrations (r=0.414, 0.465; P＜0.05). There was a significant negative correlation between SCP blood flow density and IL-6 (r=0.401, P＜0.05). ConclusionThere was a significant correlation between the concentration of aqueous cytokines in DME patients and the morphological structure of macular area and the damage degree of microvessels around macular area.