USER MANUAL (Instruction for Use) SW 6.1
Treatment Selection
Version 6.1.6 dated 2020-01-31 EN Page 162 of 201
8.5.4 Dynamic Cyclotorsion Correction
The cyclotorsional movement of the eye during the surgery is corrected with the Dynamic
Cyclotorsional Correction (DCC). A reference image is captured by the eye tracking system at the
beginning of the ablation process.
During the procedure the eye tracker captures images of the iris and blood vessel structures in
the sclera, calculates the amount of cyclotorsion and corrects the profile accordingly. This
process is called Dynamic Cyclotorsional Correction (DCC).
The reference image for the Dynamic Cyclotorsional Correction is taken when the eye tracker is
initialized for the first time, shortly before the ablation in the Treatment step of the Treatment
Assistant Manager. The Dynamic Cyclotorsion Control starts automatically.
IMPORTANT NOTE
The flap lift should be performed directly after the static cyclotorsion
measurement was completed and before the particle aspiration system is
brought into treatment position to ensure correct initialization of the DCC
function.
The time frame between Static Cyclotorsional Correction and initialization
should be as short as possible to avoid unnecessary dehydration of the eye
and to ensure correct initialization of the DCC function.
If the eye rotates during the treatment the profile will be rotated accordingly. The measured and
corrected cyclotorsional angle is displayed in the DCC field on the right side the eye tracker live
image. For reliable DCC measurement the limbus diameter shall be within the range of 10.0 ± 0.2
mm – 13.6 ± 0.2 mm and the pupil diameter shall be within the range of 1,5 mm – 6 mm ± 0.2
mm. After Start of the DCC measurement, the pupil size shall not change more than 30%.
In addition, the green cross, which indicates the ablation center in the eye tracker live image, will
be rotated to show that a dynamic cyclotorsion is measured.
If the Dynamic Cyclotorsion Correction cannot calculate an angle, due to missing structures or
exceeding the measurement range, the last measured angle will considered for the treatment but
will be decreased to 0 degrees if no new valid torsion angle can be measured.
If during an AMARIS treatment the eye-tracker is switched off, then the SCC and the DCC
information will be lost/ignored and the treatment will continue without any SCC or DCC
compensation. If later on during the same treatment the eye-tracker will be turned on again, the
original SCC value will be used to compensate and the DCC will start with the new reference from
the moment of turning on the tracker again.
The green crosshair then rotates back to 0° in this case. If a valid DCC angle can be captured again
this value will be considered for the treatment.
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