AIM:To explore the changes and influencing factors of macular retinal blood flow density in patients with proliferative diabetic retinopathy(PDR)after vitrectomy, and establish a predictive model.

METHODS: The clinical data of 173 patients with 173 eyes in PDR who underwent vitrectomy in our hospital from June 2019 to June 2021 were analyzed retrospectively. According to the changes of macular retinal blood flow density after operation, the patients were divided into normal group(118 cases with 118 eyes)and descending group(55 cases with 55 eyes). The general data, preoperative laboratory examination index and intraoperative condition of the two groups were compared. Multivariate Logistic regression was used to analyze the factors affecting the changes of retinal blood flow density in macular area after operation. Construct the line chart prediction model and evaluate its prediction efficiency.

RESULTS: The course of diabetes, proportion of patients with complicated maculopathy, serum TC, TG, LDL-C, HbA1c, vascular occlusion and hyperplastic retinal traction in the decreasing group were significantly higher than those in the normal group, while HDL-C was significantly lower than that in the normal group(P<0.05). Multivariate Logistic regression analysis showed that course of diabetes > 17a(OR=4.526), complicated maculopathy(OR=4.983), HbA1c > 6.25%(OR=4.283), vascular occlusion(OR=5.216)and hyperplastic retinal traction(OR=4.765)were all risk factors of the decrease of macular retinal blood flow density after operation(P<0.05). The line chart prediction model has good differentiation and accuracy, and has high prediction value.

CONCLUSION: Course of diabetes, complicated maculopathy, HbA1c, vascular occlusion and proliferative retinal traction are all related to the decrease of macular retinal blood flow density after vitrectomy with PDR. Understanding the risk factors is beneficial to surgical decision-making.