Table 2 The measurement repeatability of Corvis ST in thin, normal and thick corneas.

From: Assessment of corneal biomechanics, tonometry and pachymetry with the Corvis ST in myopia

 

Mean ± SD

Sw

Repeatability limit, r

IOP, mmHg

Corneathin

14.00 ± 1.57

0.975

2.701

Corneanormal

14.93 ± 1.75

0.997

2.761

Corneathick

16.31 ± 1.79

0.897

2.485

bIOP, mmHg

Corneathin

14.72 ± 1.48

0.948

2.627

Corneanormal

14.60 ± 1.55

0.957

2.650

Corneathick

14.72 ± 1.57

0.777

2.153

CCT(c), µm

Corneathin

515.30 ± 16.89

6.165

17.078

Corneanormal

557.16 ± 13.35

6.640

18.393

Corneathick

601.48 ± 17.89

7.658

21.213

DA ratio 2

Corneathin

4.99 ± 0.42

0.205

0.568

Corneanormal

4.51 ± 0.33

0.232

0.644

Corneathick

4.13 ± 0.29

0.139

0.386

IR, mm−1

Corneathin

9.27 ± 0.87

0.403

1.117

Corneanormal

8.57 ± 0.91

0.514

1.423

Corneathick

7.55 ± 0.76

0.360

0.996

ARTh

Corneathin

431.92 ± 77.08

59.239

164.090

Corneanormal

456.55 ± 91.09

53.466

148.100

Corneathick

527.10 ± 92.06

61.090

169.219

SP-A1, mmHg/mm

Corneathin

79.21 ± 9.04

4.880

13.519

Corneanormal

91.56 ± 9.79

6.128

16.974

Corneathick

102.54 ± 9.27

7.719

21.380

Arc length, mm

Corneathin

− 0.13 ± 0.02

0.012

0.034

Corneanormal

− 0.14 ± 0.02

0.014

0.039

Corneathick

− 0.15 ± 0.02

0.013

0.036

Defle A, mm

Corneathin

1.00 ± 0.09

0.035

0.098

Corneanormal

0.96 ± 0.09

0.036

0.099

Corneathick

0.90 ± 0.08

0.032

0.089

DefleA ratio 2

Corneathin

6.55 ± 0.77

0.541

1.499

Corneanormal

5.73 ± 0.71

0.570

1.578

Corneathick

5.18 ± 0.72

0.390

1.080

EMo, mm

Corneathin

0.27 ± 0.07

0.041

0.125

Corneanormal

0.26 ± 0.06

0.031

0.086

Corneathick

0.26 ± 0.06

0.030

0.083

ICR, mm−1

Corneathin

0.16 ± 0.01

0.007

0.019

Corneanormal

0.16 ± 0.02

0.009

0.025

Corneathick

0.14 ± 0.01

0.007

0.019

A1L, mm

Corneathin

2.19 ± 0.22

0.313

0.868

Corneanormal

2.27 ± 0.22

0.302

0.836

Corneathick

2.45 ± 0.17

0.283

0.783

A1V, ms−1

Corneathin

0.16 ± 0.02

0.010

0.029

Corneanormal

0.15 ± 0.02

0.011

0.030

Corneathick

0.14 ± 0.02

0.010

0.028

A1T, ms

Corneathin

7.34 ± 0.24

0.145

0.402

Corneanormal

7.53 ± 0.26

0.147

0.408

Corneathick

7.68 ± 0.28

0.154

0.427

A2L, mm

Corneathin

1.76 ± 019

0.309

0.857

Corneanormal

1.89 ± 0.23

0.275

0.761

Corneathick

2.19 ± 0.29

0.339

0.940

A2V, ms−1

Corneathin

− 0.29 ± 0.02

0.018

0.050

Corneanormal

− 0.29 ± 0.03

0.018

0.051

Corneathick

− 0.28 ± 0.02

0.016

0.044

A2T, ms

Corneathin

22.11 ± 0.30

0.180

0.499

Corneanormal

22.11 ± 0.35

0.200

0.554

Corneathick

22.00 ± 0.34

0.202

0.559

HCT, ms

Corneathin

17.28 ± 0.24

0.309

0.855

Corneanormal

17.31 ± 0.26

0.295

0.818

Corneathick

17.30 ± 0.28

0.265

0.734

PD, mm

Corneathin

5.13 ± 0.21

0.110

0.306

Corneanormal

5.06 ± 0.24

0.098

0.272

Corneathick

4.94 ± 0.23

0.101

0.280

HCR, mm−1

Corneathin

6.54 ± 0.54

0.361

1.000

Corneanormal

6.88 ± 0.62

0.570

1.579

Corneathick

7.52 ± 0.54

0.548

1.518

Def A, mm

Corneathin

1.14 ± 0.10

0.043

0.119

Corneanormal

1.11 ± 0.10

0.050

0.113

Corneathick

1.05 ± 0.08

0.033

0.091

CBI

Corneathin

0.55 ± 0.31

0.228

0.632

Corneanormal

0.27 ± 0.26

0.157

0.435

Corneathick

0.05 ± 0.10

0.076

0.210

TBI

Corneathin

0.52 ± 0.24

0.094

0.261

Corneanormal

0.33 ± 0.26

0.079

0.218

Corneathick

0.23 ± 0.21

0.070

0.195

SSI

Corneathin

0.87 ± 0.14

0.056

0.157

Corneanormal

0.88 ± 0.13

0.053

0.148

Corneathick

0.96 ± 0.13

0.053

0.147

  1. IOP intraocular pressure, bIOP biomechanically corrected IOP, CCT(c) central corneal thickness by Corvis ST, DA ratio 2 deformation amplitude ratio(2 mm), IR Integrated radius (mm−1), ARTh Ambrósio’s relational thickness, SP-A1 stiffness parameter at first applanation, Arc length the change of arc length during the deformation response within 3.5 mm horizontal distance from the apex both nasally and temporally, Defle A deflection amplitude, DefleA ratio 2 deflection amplitude ratio at 2 mm, EMo whole eye movement, ICR inverse concave radius, A1L applanation 1 length, A1V applanation 1 velocity, A1T applanation 1 time, A2L applanation 2 length, A2V applanation 2 velocity, A2T applanation 2 time, HCT time to highest concavity, PD peak distance, HCR highest concavity radius, Def A deformation amplitude, CBI Corvis biomechanical index, TBI Tomographic and biomechanical index, SSI Stress strain index SD standard deviation, Sw within-subject standard deviation, r repeatability limit.
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