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. 2021 Feb 18;14(2):228–239. doi: 10.18240/ijo.2021.02.08

Table 2. Mean range of the studied parameters in normal, SKCN, and KCN eyes.

Parameters Normal SKCN KCN P (ANOVA) P1 P2
Pentacam
 Curvature based
  Front K1 (D) 42.972±1.538 43.122±1.718 45.697±2.745 <0.001 NS <0.001
  Front K2 (D) 44.654±1.695 44.681±1.894 49.036±3.317 <0.001 NS <0.001
  Front Kmax (D) 45.062±1.754 45.826±2.077 53.795±4.642 <0.001 NS <0.001
  Back K1(D) -6.075±0.248 -6.110±0.300 -6.684±0.630 <0.001 NS <0.001
  Back K2 (D) -6.519±0.306 -6.527±0.349 -7.374±0.675 <0.001 NS <0.001
  Back Kmax (mm) -6.290±0.255 -6.306±0.302 -7.001±0.626 <0.001 NS <0.001
  ARC (mm) 7.707±0.261 7.613±0.314 6.817±0.472 <0.001 NS <0.001
  PRC (mm) 6.278±0.253 6.100±0.326 5.188±0.487 <0.001 0.012 <0.001
  ISV 19.632±8.197 26.114±10.131 72.814±30.621 <0.001 NS <0.001
  IVA 0.109±0.041 0.227±0.132 0.784±0.413 <0.001 0.013 <0.001
  KI 1.021±0.019 1.055±0.032 1.200±0.106 <0.001 0.005 <0.001
  CKI 1.007±0.005 1.009±0.011 1.047±0.037 <0.001 NS <0.001
  I-S value (D) 0.122±0.530 1.275±0.956 5.557±3.277 <0.001 0.001 <0.001
  KISA 162.297±679.62 275.438±1340.31 411.936±751.65 <0.001 NS <0.001
 Elevation based
  IHA 5.628±4.396 12.877±9.562 32.064±24.694 <0.001 0.014 <0.001
  IHD 0.009±0.005 0.024±0.017 0.107±0.057 <0.001 0.034 <0.001
 Pachymetric
  TCP (µm) 541.809±31.78 507.734±30.82 461.057±40.35 <0.001 <0.001 <0.001
  PPImax 1.287±0.204 1.658±0.415 2.710±0.835 <0.001 <0.001 <0.001
  ARTmax 432.971±78.40 327.253±90.67 187.129±64.320 <0.001 <0.001 <0.001
 Integrated
  BADD 1.069±0.678 2.445±1.260 7.211±3.081 <0.001 <0.001 <0.001
  PRFI 0.105±0.100 0.536±0.345 0.955±0.962 <0.001 <0.001 <0.001
Sirius
 Curvature based
  K1 (D) 42.156±4.891 42.950±1.652 45.274±2.508 <0.001 NS <0.001
  K2 (D) 44.612±2.930 44.458±1.821 48.257±3.023 <0.001 NS <0.001
  Curve (Kmax, D) 45.425±2.098 46.619±2.213 54.118±4.406 <0.001 NS <0.001
  SIf 0.011±0.474 1.278±1.102 5.993±3.579 <0.001 0.001 <0.001
  SIb 0.097±0.982 0.421±0.380 1.613±0.896 <0.001 0.040 <0.001
 Elevation based
  KVf 4.015±1.625 7.861±4.208 28.271±14.998 <0.001 0.03 <0.001
  KVb 11.309±3.448 20.392±10.714 66.057±34.190 <0.001 0.024 <0.001
 Pachymetric
  Thkmin (µm) 539.221±32.953 501.127±32.421 445.219±86.449 <0.001 <0.001 <0.001
Corvis
 Deformation
  A1L (mm) 2.407±0.292 2.220±0.332 2.107±0.353 <0.001 0.002 <0.001
  A2L (mm) 2.063±0.391 1.868±0.288 1.660±0.339 <0.001 0.002 <0.001
  A1T (ms) 7.595±0.468 7.255±0.506 6.965±0.424 <0.001 <0.001 <0.001
  A2T (ms) 21.041±0.385 21.171±0.425 21.386±0.462 <0.001 NS <0.001
  A1V (mm/ms) 0.118±0.015 0.128±0.019 0.140±0.027 <0.001 0.015 <0.001
  A2V (mm/ms) -0.255±0.023 -0.268±0.028 -0.286±0.037 <0.001 0.034 <0.001
  DAratio1 1.572±0.050 1.618±0.066 1.688±0.082 <0.001 <0.001 <0.001
  DAratio2 4.114±0.344 4.505±0.483 5.170±0.724 <0.001 <0.001 <0.001
  HCDA (mm) 0.942±0.079 0.991±0.105 1.055±0.115 <0.001 0.012 <0.001
 Deflection
  A1DfA (mm) 0.100±0.006 0.100±0.009 0.109±0.011 <0.001 NS <0.001
  A2DfA (mm) 0.110±0.011 0.108±0.014 0.118±0.013 <0.001 NS <0.001
  HCDfA (mm) 0.825±0.080 0.869±0.102 0.931±0.119 <0.001 0.030 <0.001
  InvRadMax (mm) 0.159±0.016 0.172±0.020 0.199±0.031 <0.001 0.002 <0.001
  IntRC1 (mm−1) 6.873±0.834 7.759±1.278 9.508±2.027 <0.001 0.001 <0.001
 Integrated
  ARTh 519.448±138.67 403.783±122.3 229.875±92.76 <0.001 <0.001 <0.001
  SPA1(mm Hg/mm) 110.490±15.99 92.135±19.33 70.497±18.99 <0.001 <0.001 <0.001
  CBI 0.128±0.247 0.481±0.410 0.933±0.206 <0.001 <0.001 <0.001
  TBI 0.222±0.229 0.702±0.384 0.998±0.010 <0.001 <0.001 <0.001

K1: Keratometry in flat meridian; K2: Keratometry in steep meridian; Kmax: Max keratometry; ARC: Anterior radius of curvature in the 3 mm zone; PRC: Posterior radius of curvature in the 3.0 mm zone; TCP: Thinnest corneal point; PPImax: Maximum of pachymetric progression index; ARTmax: Maximum Ambrosio's relational thickness; ISV: Index of surface variance; IVA: Index of vertical asymmetry; KI: Keratoconus index; CKI: Central keratoconus index; IHA: Index of height asymmetry; IHD: Index of height decentration; I-S value: Inferior-superior difference value; KISA: Keratoconus percentage index; BADD: Belin/Ambrosio enhanced ectasia total deviation value; PRFI: Pentacam random forest index; ThkMin: Thinnest corneal thickness; SIf and SIb: Symmetry index of front and back of corneal curvature; KVf and KVb: Keratoconus vertex front/back; AL1, AL2: The length of flattened cornea at first/second applanations; A1T, A2T: Time from the beginning of air-puff until the first/second applanation; AV1, AV2: Corneal velocity at the first/second applanations; DAratio1, DAratio2: Maximum deformation amplitude ratio at 1 mm and 2 mm; HCDA: Deformation amplitude of the highest concavity; A1DfA, A2DfA: Deflection amplitude of the first/second applanation; HCDfA: Deflection amplitude of the highest concavity; InvRadmax: Maximum inverse radius; IntRC1: Integrated radiu; ARTh: Ambrosio relational thickness to the horizontal profile; SPA1: Stiffness parameter at first applanation; CBI: Corneal biomechanical index; TBI: Topographic and biomechanical index; SKCN: Subclinical keratoconus; KCN: Keratoconus; D: Diopter; NS: Not significant. 1The comparison between normal and SKCN eyes; 2The comparison between normal and KCN.