Table 2 The values of the 36 indices in ectatic and non-ectatic eyes and their diagnostic accuracy.

From: Diagnostic accuracy of different keratoconus detection indices of pentacam in paediatric eyes

 

Normal eyes (432)

KC and FFKC (48)

Diagnostic Accuracy

Mean

95% CI

Mean

95% CI

AUC

95% CI

Youden criterion

95% CI

Sensitivity

Specificity

P from CAIRO 8

1

CAIRO 8

−2.51

−2.77 to −2.25

12.87

10.44 to 15.30

0.979

0.962 to 0.990

>2.71

>1.36 to >6.67

89.6

97.2

 

2

ART max

461.6

452.1 to 471.1

204.8

179.7 to 229.9

0.967

0.947 to 0.981

≤296

≤259 to ≤366

85.4

96.5

0.346

3

PPI max

1.206

1.181 to 1.230

2.583

2.296 to 2.871

0.966

0.946 to 0.981

>1.7

>1.3 to >1.8

85.4

96.8

0.327

4

ART avg

578.6

568.3 to 588.8

283

250.6 to 315.4

0.964

0.943 to 0.979

≤443

≤428 to ≤443

91.7

91.9

0.213

5

PPI avg

0.95

0.935 to 0.965

1.829

1.647 to 2.012

0.961

0.939 to 0.976

>1.1

>1 to >1.2

89.6

92.8

0.188

6

KI

1.021

1.019 to 1.023

1.17

1.139 to 1.201

0.952

0.929 to 0.969

>1.04

>1.03 to >1.05

91.7

88.0

0.162

7

BE from BFTE

1.5

1.3 to 1.8

35.4

28.2 to 42.5

0.953

0.930 to 0.970

>3

>2 to >6

85.4

97.2

0.129

8

TKC

0.0

0.0 to 0.1

1.9

1.6 to 2.1

0.942

0.917 to 0.961

>0

>0 to >0.5

89.6

94.4

0.079

9

IHD

0.0115

0.0109 to 0.0121

0.069

0.0547 to 0.0833

0.947

0.923 to 0.965

>0.025

>0.019 to >0.027

83.3

97.2

0.071

10

BE

7.0

6.5 to 7.4

40.2

34.3 to 46.2

0.947

0.923 to 0.965

>18

>15 to >25

87.5

98.8

0.047

11

CKI

1.01

1.009 to 1.010

1.061

1.048 to 1.075

0.931

0.905 to 0.952

>1.02

>1.01 to >1.02

79.2

97.9

0.023

12

IVA

0.161

0.153 to 0.168

0.641

0.536 to 0.745

0.941

0.915 to 0.960

>0.26

>0.23 to >0.32

89.6

92.1

0.020

13

FE from BFTE

0.8

0.7 to 0.9

14.2

11.1 to 17.3

0.928

0.901 to 0.949

>11

>6 to >13

87.5

99.5

0.018

14

PPI min

0.659

0.646 to 0.673

1.398

1.221 to 1.575

0.925

0.898 to 0.947

>0.9

>0.7 to >1

75.0

97.2

0.007

15

FE from BFS

4.4

4.2 to 4.7

19.4

16.1 to 22.7

0.92

0.893 to 0.943

>8

>7 to >10

85.4

94.4

0.007

16

K max front

45.763

45.573 to 45.953

54.184

51.973 to 56.395

0.877

0.844 to 0.905

>48.82

>46.9 to >49.34

75.0

93.8

0.002

17

TP

534.9

531.2 to 538.5

450.271

435.0 to 465.5

0.909

0.880 to 0.934

≤500

≤476 to ≤521

81.3

83.8

0.001

18

ISV

30.1

29.2 to 31.0

72.4

62.1 to 82.7

0.875

0.842 to 0.903

>45

>39 to >46

77.1

94.9

0.001

19

Ecc Sph

0.671

0.660 to 0.683

0.962

0.892 to 1.032

0.862

0.828 to 0.892

>0.81

>0.79 to >0.88

75.0

93.5

0.001

20

Pachy apex

536.9

532.0 to 541.7

460.1

444.5 to 475.8

0.886

0.855 to 0.913

≤505

≤490 to ≤520

81.3

83.3

0.001

21

Pachy pupil

538.1

534.5 to 541.7

463.6

448.4 to 478.7

0.885

0.853 to 0.912

≤514

≤497 to ≤519

87.5

75.2

0.001

22

Tilt

0.234

0.222 to 0.245

0.658

0.560 to 0.756

0.896

0.865 to 0.921

>0.41

>0.39 to >0.5

79.2

91.9

<0.001

23

TNP apex

42.49

42.24 to 42.74

47.3

45.87 to 48.74

0.842

0.807 to 0.874

>43.6

>42.9 to >44

83.3

73.2

<0.001

24

K1

42.348

42.182 to 42.514

46.342

45.086 to 47.597

0.827

0.790 to 0.860

>43.7

>42.6 to >45.5

72.9

80.3

<0.001

25

K2

45.157

44.978 to 45.337

50.121

48.475 to 51.767

0.816

0.779 to 0.850

>46.8

>45.6 to >48.5

72.9

81.7

<0.001

26

IHA

6.55

6.02 to 7.08

25.10

18.11 to 32.10

0.802

0.763 to 0.837

>9.9

>4.1 to >18

68.8

78.0

<0.001

27

Irregularity

0.0206

0.0197 to 0.0215

0.0386

0.0311 to 0.0460

0.775

0.735 to 0.812

>0.02

>0.018 to >0.03

79.2

60.4

<0.001

28

K Max front y

0.391

0.269 to 0.513

−0.721

−0.969 to −0.474

0.747

0.706 to 0.786

≤0.19

≤−0.13 to ≤1.17

89.6

52.6

<0.001

29

K mean

43.906

43.722 to 44.090

47.141

45.707 to 48.574

0.727

0.685 to 0.767

>45.15

>43.8 to >46.05

60.4

77.3

<0.001

30

ACD

3.106

3.077 to 3.136

3.345

3.219 to 3.471

0.704

0.661 to 0.745

>3.41

>3.05 to >3.65

50.0

84.3

<0.001

31

TP y

−0.372

−0.398 to −0.346

−0.501

−0.600 to −0.403

0.621

0.576 to 0.665

≤−0.44

≤−0.53 to ≤ −0.07

66.7

59.3

<0.001

32

Keratometric astigmatism

2.81

2.68 to 2.94

3.78

3.03 to 4.53

0.607

0.562 to 0.651

>3.1

>0.7 to >4.4

64.6

59.0

<0.001

33

ACV

185.9

182.50 to 189.30

194.57

183.84 to 205.30

0.582

0.536 to 0.627

>179

>115 to >235.3

70.8

46.5

<0.001

34

ACA

37.89

37.24 to 38.53

39.23

36.92 to 41.54

0.561

0.516 to 0.606

>42.8

>32.2 to >46.2

35.4

80.6

<0.001

35

K Max front x

−0.108

−0.142 to −0.0744

−0.0281

−0.121 to 0.0643

0.558

0.513 to 0.603

>−0.2

>−0.61 to >0.07

81.3

32.4

<0.001

36

TP x

−0.566

−0.599 to −0.533

−0.526

−0.597 to −0.455

0.553

0.508 to 0.598

>−0.65

>−0.91 to > −0.42

70.8

42.6

<0.001

  1. CAIRO 8 Corneal Assessment Index from the Relational thickness and other OCULUS values analysed for an 8-mm zone, ART max Ambrosio’s relational thickness maximum, PPI Max maximum pachymetric progression Index, ART avg Ambrosio’s relational thickness average, PPI avg average pachymetric progression index, KI keratoconus index, BE BFTE back elevation from the best-fit toric ellipsoid, TKC topographic keratoconus indices, IHD index of height decentration, BE back elevation from the best-fit sphere, CKI central keratoconus index, IVA index of vertical asymmetry, FE BFTE front elevation from the best-fit toric ellipsoid, PPI min minimum pachymetric progression index, FE BFS front elevation from the best-fit sphere, K max front keratometry of the steepest point of the front surface, TP corneal thickness at the thinnest point, ISV index of surface variance, Ecc Sph mean eccentricity in the central 30 degrees by Fourier analysis, Pachy apex corneal thickness at the apex, Pachy pupil corneal thickness at the point corresponding to the pupil centre, Tilt tilt by Fourier analysis, TNP Apex true net power at the corneal apex, K1 keratometric power of the flat meridian, K2 keratometric power of the steep meridian, IHA index of height asymmetry, Irregularity high-order irregularity by Fourier analysis (other than spherical power and asphericity, tilt, and astigmatism), K Max y Front steepest point of the front surface keratometry displacement in the y-axis, K mean mean curvature power of the cornea within the central 3-mm circle expressed in diopters, ACD internal anterior chamber depth, TP y thinnest point displacement in the y-axis, keratometric astigmatism keratometric astigmatism (absolute value), ACV anterior chamber volume at 10-mm diameter, ACA maximum anterior chamber angle in the horizontal meridian, K Max Front x steepest point of the front surface keratometry displacement in the x-axis, TP x thinnest point displacement in the x-axis.
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