Topometric and Tomographic Indices for the Diagnosis of Keratoconus

Abstract

Purpose: To compare topometric (front surface curvature) and tomographic (3D corneal shape) indices for diagnosing keratoconus. Methods: Pentacam data from one eye randomly selected of 200 normals (N) and 177 keratoconus (KC) were analyzed. Tomographic and topometric indices were tested. Receiver operating characteristic (ROC) curves were calculated, along with pairwise comparisons. Results: All tested variables had significant differences among N and KC (Mann-Whitney, p < 0.001). Most accurate tomographic indices had higher AUC than best topometric ones (DeLong, p < 0.05). Belin-Ambrosio D (BAD-D) had AUC of 1.00 (sensitivity 100.0%; specificity 98.5%). Conclusion: Tomographic data was superior than topometric data to detect keratoconus. The BAD-D was an enhanced approach for detecting keratoconus.