Abstract:Abstract Objective: diabetic retinopathy (DR) is one of the serious complications of diabetes and a leading cause of blindness at working age worldwide. Although panretinal photocoagulation (PRP) is the standard treatment, Dr treated by PrP still has a high risk of progression. Therefore, this study aimed to evaluate the risk factors and to establish a model for predicting the worsening of diabetic retinopathy (DR worsening) over a period of five years after PrP. Methods: patients diagnosed with severe nonproliferative diabetic retinopathy or proliferative diabetic retinopathy and treated with PRP were included and randomly assigned into a validation cohort. Multivariate logistic regression analysis was used to screen potential risk factors for worsening DR in the cohort. The model was then built after the inclusion of significant independent risk factors and further validated by discrimination and correction. Results: a total of 271 patients were included and 56.46% had an outcome of worsening Dr. In the observational cohort (n = 135), age (odds ratio [or] = 0.94, 95% confidence interval [CI] = 0.90-0.98), baseline best corrected visual acuity (LogMAR) (or = 10.74, 95% CI 1.84-62.52), diabetic nephropathy (or = 9.32, 95% CI 1.49-58.46), and hyperlipidemia (or = 3.34, 95% CI 1.05-10.66) were included as independent risk factors in the predictive model. The area under the receiver operating characteristic curve and adjusted slope were 0.79, 0.96 (95% confidence interval 0.60 to 1.31) and 0.79, 1.00 (95% confidence interval 0.66 to 1.34) for the observational and control cohorts, respectively. Two risk groups were established according to the optimal cutoff value of predicted probability, and the actual probability of occurrence was 34.90% and 82.79% in the low - and high-risk groups, respectively (P < 0.001). Conclusions: This study developed a new model and validated internally to predict the likelihood of worsening Dr over a 5-year period after treatment with PRP. This model may serve as a rapid risk assessment system for clinically predicting Dr exacerbations, identifying high-risk individuals for Dr exacerbations early, and prescribing additional treatments.