Diagnostics
Multivariate Analysis of the Spatial Distance Between the Corneal Thinnest Point and Maximum Keratometry in Keratoconic Corneas: Association with Disease Severity
Par Umberto Camellin, Marco Lombardo, Francesco Franchina et 6 autres.
Contenu en anglais
Résumé
Background
This study quantified the planar distance (D, mm) between the corneal thinnest point (TP) and maximum keratometry (Kmax) and examined its association with tomographic features and keratoconus severity.
Methods
Tomographic data from 140 patients (280 eyes) with bilateral manifest keratoconus were obtained with a Scheimpflug camera (Pentacam HR; Oculus, Wetzlar, Germany). D was calculated from the Cartesian coordinates of TP and Kmax. A multiple linear regression model included simulated anterior average keratometry (SimKavg), anterior and posterior radii of curvature (ARC and PRC), and anterior Q-value (Q-ant). Inference used patient-clustered robust standard errors. Internal validation comprised repeated grouped 10-fold cross-validation and patient-level bootstrap resampling. Performance was assessed using R2, root-mean-square error (RMSE), mean absolute error (MAE), and Bland–Altman limits of agreement.