Influence of preoperative HbA1c level on posterior membrane opacity after phacoemulsification in diabetic patients and analysis of threshold effect

AIM:To analyze the predictive value and threshold effect of preoperative glycated hemoglobin(HbA1c)level on posterior capsular opacification(PCO)in diabetic cataract patients.METHODS:Retrospective study. A total of 106 diabetic patients(106 eyes)with cataract treated in our hospital from September 2018 to September 2020 were collected. The patients were divided into PCO group(52 cases, 52 eyes)and non-PCO group(54 cases, 54 eyes)according to whether PCO occurred at 36 mo after surgery. The risk factors affecting postoperative PCO were analyzed. The threshold effect of HbA1c level on the occurrence of postoperative PCO was analyzed. The predictive value of preoperative HbA1c level in postoperative PCO was evaluated using the receiver operating characteristic(ROC)curve. The prediction model was constructed, and Bootstrap resampling was used to verify the prediction model, and the differentiation and accuracy of the model were evaluated.RESULTS: There were significant differences in diabetes course, diabetic retinopathy, fasting blood glucose, 2 h postprandial blood glucose, preoperative HbA1c, axial length and nuclear grade between PCO and non-PCO groups(P