Table 1.
Parameters | Abbreviation | Description |
---|---|---|
Biomechanically corrected intraocular pressure | bIOP | Derived by finite element simulations that take into account the influence of central corneal thickness, age, and DCR parameters |
First applanation A1 | A1 | Moment at the first applanation of the cornea during the air puff |
A1 time (ms) | A1T | Time from start to A1 |
A1 velocity (m/s) | A1V | Velocity of corneal apex at A1 |
A1 deformation amplitude | A1DA | Moving distance of the corneal apex from the initial position to that at the A1 Time |
A1 deflection length | A1DL | Length of the flattened cornea at A1 |
A1 deflection amplitude | A1DeflA | Similar to A1DA without whole eye movement |
A1 delta arc length | A1dArclength | Change in Arclength from initial state to A1, in a defined 7-mm zone |
Second applanation A2 | A2 | Moment at the first applanation of the cornea during the air puff |
A2 time (ms) | A2T | Time from start to A2 |
A2 velocity (m/s) | A2V | Velocity of corneal apex at A2 |
A2 deformation amplitude | A2DA | Moving distance of the corneal apex from the initial position to that at A2 time |
A2 deflection length | A2DL | Length of the flattened cornea at A2 |
A2 deflection amplitude | A2DeflA | Similar to A2DA without whole eye movement |
A2 delta arc length | A2dArclength | Change in arclength from initial state to A2, in a defined 7-mm zone |
Highest concavity | HC | Moment that the cornea assumes its maximum concavity during the air puff |
HC time | HCT | Time to reach the maximum deformation |
Radius (mm) | Rad | Central curvature radius at the highest concavity |
HC deformation amplitude | HCDA | Distance of the corneal apex movement from the initiation of the deformation to the highest concavity |
HC deflection length | HCDL | Length of the flattened cornea at highest concavity |
HC deflection amplitude | HCDeflA | Similar to HCDA without whole eye movement |
Peak distance | PD | Distance between the two surrounding peaks of the cornea at the highest concavity |
HC delta Arc length | HC dArclength | Change in arclength during the highest concavity moment from the initial state, in a defined 7-mm zone |
Maximum | Max | Similar as HC |
Max deformation amplitude | Max DA | Distance of the corneal apex movement from the initiation of the deformation to the highest concavity |
Max deflection amplitude | Max DeflA | Similar to HCDeflA |
Max delta arc length | Max dArclength | Change in arclength during the highest concavity moment from the initial state, in a defined 7-mm zone |
Vinciguerra screening parameters | ||
Deformation amplitude ratio max (2 mm) | DA ratio max | Ratio between the deformation amplitude at the apex and the average deformation amplitude measured at 2 mm from the center |
Ambrósio’s relational thickness to the horizontal profile | ARTh | Describes thickness profile in the temporal-nasal direction and defined as corneal thickness thinnest to pachymetric progression |
Integrated radius | INR | Area under the inverse concave radius versus time curve |
Stiffness parameter at A1 | SP A1 | Describes corneal stiffness as defined by resultant pressure (Pr) divided by deflection amplitude at A1 |
Corvis biomechanical index | CBI | Overall biomechanical index for keratoconus detection |
HC: Highest concavity, DCR: Dynamic corneal response