Nomogram for predicting non-proliferative vitreoretinopathy probability after vitrectomy in eyes with rhegmatogenous retinal detachment.

AIM: To identify the risk factors for postoperative proliferative vitreoretinopathy (PVR) in patients with primary rhegmatogenous retinal detachment (RRD) and develop a nomogram for predicting postoperative PVR-free probability. METHODS: A total of 741 patients (741 eyes) diagnosed with primary RRD who underwent first surgery in the same hospital were retrospectively reviewed and randomly assigned with 521 to the training set and 220 to the validation set. Univariate and multivariate logistic regression analyses were performed in the training cohort to determine risk factors to construct a nomogram for predicting the 3-, 4-, 5-, and 6-month postoperative PVR-free probabilities. Nomogram performance was estimated by the concordance index (C-index), calibration plot, and the area receiver operating characteristic (ROC) curve. RESULTS: A nomogram was constructed based on the preoperative PVR, silicone oil tamponade time (SOTT), photocoagulation energy (PE), retinal tear size (RTS), and hypertension. In the training set, the C-index of the nomogram was 0.896, 0.936, 0.961, and 0.972 at 3, 4, 5, and 6mo, respectively. The C-index values in the validation set were 0.860, 0.936, 0.951, and 0.965 at 3, 4, 5, and 6mo, respectively. Decision-curve analysis indicated that only the 4-, 5-, and 6-month nomograms had significant net benefits over a large threshold probabilities interval. CONCLUSION: Preoperative PVR, SOTT, PE, RTS, and hypertension are significant risk factors for postoperative PVR formation in patients with primary RRD. The proposed nomogram can effectively predict the 4-, 5-, and 6-month PVR-free probabilities after surgery and assist in making clinical decisions during follow-up.