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<0.05). Duration of diabetes ≥12 a, presence of DR, fasting blood glucose ≥8 mmol/L, 2 h postprandial blood glucose ≥12 mmol/L, preoperative HbA1c ≥7%, axial length ≥30 mm, and nuclear grade Ⅲ or above were all influencing factors for postoperative PCO(P<0.05). Curve fitting found that the probability of postoperative PCO showed an increasing trend with the increase of HbA1c level. Threshold effect analysis found that the incidence of postoperative PCO increased with the increase of HbA1c level when HbA1c≥7%. Sensitivity analysis showed that E value=2.129. The analysis of the correlation effect between preoperative HbA1c and the degree of PCO after phacoemulsification showed that the adjusted preoperative HbA1c level was an independent factor affecting the degree of PCO in diabetic patients(OR=1.65, 95% CI: 1.42-1.76, P=0.021). PCO outcome in diabetic cataract patients was indicated when the predictive model P=0.6, and the prediction accuracy of the model was 88.51%. Sensitivity and specificity were 86.33% and 86.82%, respectively.

CONCLUSION:Duration of diabetes, presence of DR, fasting blood glucose, 2 h postprandial blood glucose, preoperative HbA1c, axial length, and nuclear grade were independent risk factors for postoperative PCO in diabetic patients, and preoperative HbA1c could be used as a sensitive index to evaluate postoperative PCO.