Purpose: To externally validate the accuracy of previously published formulas for predicting proliferative vitreoretinopathy development after retinal detachment surgery.
Methods: Clinical variables from consecutive retinal detachment patients (n = 1,047) were collected from the Retina 1 Project conducted in 17 Spanish and Portuguese centers. These data were used for external validation of four previously published formulas, F1 to F4. Receiver-operating characteristic curves were used to validate the quality of formulas, and measures of discrimination, precision, and calibration were calculated for each. Concordance among the formulas was determined by Cohen kappa index.
Results: The areas under the receiver-operating characteristic curves were as follows: F1, 0.5809; F2, 0.5398; F3, 0.5964; and F4, 0.4617. F1 had the highest accuracy, 74.21%. Almost 19% of proliferative vitreoretinopathy cases were correctly classified by F1 compared with 13%, 15%, and 10% for F2, F3, and F4, respectively. There was moderate concordance between F2 and F3 but little between the other formulas.
Conclusion: After external validation, none of the formulas were accurate enough for routine clinical use. To increase its usefulness, other factors besides the clinical ones considered here should be incorporated into future formulas for predicting risk of developing proliferative vitreoretinopathy.