USER MANUAL (Instruction for Use) SW 6.1
Device / System Description
Version 6.1.6 dated 2020-01-31 EN Page 53 of 201
4.6 Laser Description
4.6.1 The Main Principle of the Excimer Laser
The high-performance excimer laser is designed for the ablation of human eye tissue.
Excimer gas lasers are stimulated with an electric pulse in a mixture of noble gases and halogens.
The output lifts the noble gas atoms to a higher energy level so that they react with the halogen
molecules and bond to them, as ArF.
These special molecules, known as excimers (excited dimers), are stable only for a short time.
They collapse and emit a high ultraviolet radiation. If the gas is arranged in an optical resonator
of two parallel mirrors, the laser effect is achieved and light impulses with very high outputs are
beamed.
The laser gas partially consumes itself during output and must be changed when the intended
energy level no longer be achieved through adjustment of laser high voltage.
The laser source used with the AMARIS is a very compact unit optimized for reliability and low
gas consumption.
The performance data listed in chapter 11 Technical Data prescribe the data of the laser and the
necessary voltage connections.
The laser source is designed for a treatment sequence in which the laser fires for max. 5 minutes
dynamically (treatment) and “rests” for 5 minutes in a static “standby” mode (OP- preparation
before and after treatment).
Besides the high-performance laser of the AMARIS, a visible low-power diode laser is also used
as an aiming laser.
4.6.2 Positioning Slit Lights
Two lamps, one slit-shaped and the other cross-shaped, are used to adjust the exact working
distance from and the center of the corneal surface. The two beams of the positioning slit lights
will be displayed on a curved surface as two white bow shaped patterns.
4.6.3 Fixation LED
The fixation LED is used for fixation of the patient's eye. The fixation LED beam is displayed on
a surface as a green, blinking point.
4.6.4 Aiming Laser
The aiming laser is guided coaxially with the excimer laser beam and, therefore, indicates the
position of the laser in the working plane. It will also follow the movements of the excimer laser
beam during the treatment.
When the eye tracker is active, the aiming laser fixates on the pupil center and will follow any
pupil movements.
If the eye tracker cannot recognize the pupil and must be therefore deactivated, the aiming laser
then points into the middle of the working plane. Use the aiming laser to center the patient
manually. During the treatment, the correct centration can be checked by releasing the footswitch
for a short moment. The aiming laser then points back to the center of ablation.
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