Experts agree that some kind of eye tracking is necessary when using
spot scanning lasers with longer procedure times. Without eye tracking,
patients would be unable to fix their gaze long enough for the procedure
to be completed.
Eye-tracking systems link the operation of the laser to the position of
the eye. The eye trackers monitor the location of the pupil and interrupt
the laser beam if the eye moves beyond a predetermined distance.
The latest eye tracking technologies include systems with 6D Iris
Recognition capabilities that allow exact correction of astigmatism. Iris
recognition ensures an exact match between the treatment target and the
actual laser treatment for every eye by calculating the precise rotational
position of the eye during surgery based on the preoperative exam. This
compensates for "cyclotorsion"- the slight rotation of the eye
that can occur when the patient changes from a sitting up to a laying
down position.
The 6D Eye-Tracking System of the Schwind Amaris Excimer laser:
