Diagnostic Sensitivity of Different Reference Bodies When Using Scheimpflug Tomography in a Myopic Population with Keratoconus
Table 3
Cutoff values between normal and keratoconus population at each measuring point with the statistical measures obtained at these cutoff values.
Parameter
Cutoff
Sensitivity
Specificity
PPV
NPV
AUC (95% CI)
BFS RMS-P
18.7
0.939
0.763
0.597
0.971
0.900 (0.870, 0.940)
BFS AA
3.50
0.585
0.941
0.787
0.858
0.760 (0.680, 0.840)
BFS PA
7.50
0.744
0.945
0.836
0.908
0.840 (0.770, 0.910)
BFS AT
5.50
0.951
0.973
0.929
0.982
0.990 (0.990, 1.000)
BFS PT
17.5
0.976
0.991
0.976
0.991
1.000 (1.000, 1.000)
BFTEFE RMS-P
7.99
0.951
0.982
0.951
0.982
0.990 (0.990, 1.000)
BFTEFE AA
1.50
0.659
0.968
0.885
0.883
0.800 (0.730, 0.870)
BFTEFE PA
4.50
0.732
0.973
0.909
0.906
0.860 (0.790, 0.920)
BFTEFE AT
1.50
0.963
0.977
0.940
0.986
0.980 (0.950, 1.000)
BFTEFE PT
8.00
1.000
0.995
0.988
1.000
1.000 (1.000, 1.000)
BFTE RMS-P
5.87
0.927
0.945
0.864
0.972
0.980 (0.960, 1.000)
BFTE AA
ā1.50
0.402
0.977
0.868
0.814
0.590 (0.510, 0.680)
BFTE PA
ā1.50
0.512
0.900
0.656
0.831
0.620 (0.520, 0.710)
BFTE AT
0.50
0.841
0.932
0.821
0.940
0.910 (0.860, 0.960)
BFTE PT
3.50
0.866
0.968
0.910
0.951
0.950 (0.920, 0.990)
AA, anterior elevation at the apex; AT, anterior elevation at the thinnest point; AUC, area under the curve; BFS, best fit sphere; BFTE, best fit toric ellipsoid; BFTEFE, best fit toric ellipsoid with fixed eccentricity; CI, confidence interval; NPV, negative predictive value; RMS-P, root mean square of posterior elevations; PA, posterior elevation at the apex; PPV, positive predictive value; PT, posterior elevation at the thinnest point.
