Appendix Velocity
Tables
Appendix
- 1
DEFAULT INDIVIDUAL VELOCITIES
Classification of Eye
Velocity [m/s]
Anterior Chamber Depth (ACD)
1532
Crystalline Lens
1640
Vitreous Length
1532
REFERENCE VELOCITIES FOR SPECIFIC
STRUCTURES
Structure
Velocity [m/s]
Cornea 1641
Anterior Chamber Depth (ACD)
1532
Crystalline Lens
1640
Vitreous Length
1532
PMMA IOL
2718
Acrylic IOL
2120
Silicone-I IOL
1049
Silicone-II IOL
980
IOL CORRECTION VALUES
IOL Material
Correction [mm]
PMMA IOL
+0.4
Acrylic IOL
+0.2
Silicone-I IOL (Velocity=1049m/s)
-0.8
Silicone-II IOL (Velocity=980m/s)
-0.4
Notes:
1. The Sonomed EZ-S
CAN
uses 2, 3, or 4
gates to measure an eye based on the “Eye
Type” selected. Individual velocities are
used for each area as shown in the table
above. The user can enter any desired
velocity to replace the default value, but this
is not recommended except in the case
where silicone oil or some other material is
present.
2. If the velocity is changed by the user for a
particular eye type, it is imperative that this
velocity be reviewed and/or changed by the
user before proceeding with further
measurements of other eye types.
3. Manual Mode permits the user to select both
the number of gates to be used as well as the
individual velocities for each structure.
Example
:
Aphakic Eye: Use two (2) gates and a
velocity of 1532m/s.
4. For Pseudophakic Modes, the EZ-S
CAN
calculates the measurement using a velocity
of 1532m/s (for the Anterior Chamber and
Vitreous lengths), and uses a correction
factor for the particular IOL material as
shown in the table to the left.
The user can enter up to 5 custom lenses
with correction factors from -2.0 to +2.0.
Appendix A
VELOCITY TABLES
