AIM:To investigate the value of optical coherence tomography angiography(OCTA)indicators in the diagnosis of diabetic retinopathy(DR), and to provide patients with diabetic nephropathy(DN)with more sensitive OCTA screening indicators to detect concurrent DR at an early stage.METHODS: A total of 200 patients who treated in the ophthalmology department of the Seventh Affiliated Hospital, Sun Yat-sen University from 2022 to 2023 were included, including 95 first-diagnosed DR patients and 105 patients without DR, and all patients underwent OCTA examination and a collection of demographics and renal function parameters. After a quality check, automated measurements of the foveal avascular zone area, vessel density(VD), and perfusion density(PD)of both 3 mm×3 mm and 6 mm×6 mm windows were obtained.RESULTS: Using random forest and multivariate Logistic regression methods, we developed a diagnostic model for DR based on 12 variables(age, FBG, SBP, DBP, HbA1c, ALT, ALP, urea/Scr, DM duration, HUA, DN, and CMT). Adding specific OCTA parameters enhanced the efficacy of the existing diagnostic model for DR(outer vessel density in 6 mm×6 mm window, AUC=0.837 vs 0.819, P=0.03). In the study of DN patients, the parameters in the 6 mm×6 mm window improved the diagnostic efficacy of DR(inner VD; outer VD; full VD; outer PD; full PD).CONCLUSION:The outer VD in the 6 mm×6 mm window can enhance the efficacy of the traditional DR diagnostic model. Meanwhile, compared with the 3 mm×3 mm window, the microvascular parameters in the 6 mm× 6 mm window focusing on DN patients can be more sensitive to diagnosing the occurrence of DR.