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. 2021 Jul 7;8:663494. doi: 10.3389/fmed.2021.663494

Table 2.

The meaning of Corvis ST parameters.

Parameter Explanation
First applanation time (AT1) Time to reach first applanation
First applanation length (AL1) Length of the deformed part of the cornea at first applanation
First applanation velocity (AV1) Corneal velocity at first applanation
Second applanation time (AT2) Time to reach second applanation
Second applanation length (AL2) Length of the deformed part of the cornea at second applanation
Second applanation velocity (AV2) Corneal velocity at second applanation
Highest concavity time (HCT) Time to reach highest concavity
Deformation amplitude (DA) Sagittal length of deformation of the apex at highest concavity
Peak distance (PD) The distance of the part of the cornea without deformation at highest concavity
Radius of curvature (Rad) Radius of curvature at highest concavity
Deformation amplitude ratio (DAR) The ratio between the deformation amplitude at the apex and the deformation amplitude at 2 mm
Integrated radius (Integr Rad) The integrated area under the inverse radius curve during the concave phase
Stiffness parameter at first applanation (SP-A1) Pressure at first applanation–Biomechanically corrected intraocular pressure/deflection amplitude at first applanation
Ambrósio's relational thickness horizontal (ARTh) The division between corneal thickness at the thinnest point and the progression index that describes the thickness increase from the thinnest point to the periphery