Table 1.

Corneal biomechanical parameters of Corvis ST.

Parameters	Definition
A1L	Cord length of the first-degree applanation
A1V	Corneal speed during the first-degree applanation
A2L	Cord length of the second-degree applanation
A2V	Corneal speed during the second-degree applanation
PD	Distance of the 2 knee's at highest concavity
Radius	Central concave curvature at highest concavity
DA	Maximum amplitude at the apex of highest concavity
CCT	Central corneal thickness
IOP	Intraocular pressure (uncorrected non-contact tonometer)
bIOP	biomechanically-corrected IOP
DARatio	The ratio between the deformation/deflection amplitude at the apex and the average deformation/deflection amplitude measured at 1 or 2 mm from the center
IR	Integrated radius, the inverse concave radius (1/R) between the first and second application events
ARTh	Ambrosio's Relational Thickness to the horizontal profile, the devision between corneal thickness at the thinnest point and the Pachymetric Progression.
SP-A1	Stiffness parameter at first applanation, the resultant pressure (Pr) decided by deflection amplitude at first applanation (A1)
CBI	Corvis Biomechanical Index, a combined biomechanical index based on different dynamic corneal response parameters, to aid the diagnosis of ectasia