Using The Aiming Beam System With The Visulas Yag Iii / Visulas Yag Iii Combi - Zeizz VISULAS YAG III Instrucciones Para El Uso

Using the aiming beam system with the
VISULAS YAG III / VISULAS YAG III Combi
The VISULAS YAG III uses a four-point aiming beam system.
If the image is free from distortion, the following aiming beam spot
patterns can be seen, depending on the position of the focus:
Spot image of
aiming beam
Aiming
beam focus
Focus anterior
to tissue
Fig. 34 Focusing the aiming beam
When working with energies of up to 1.5 mJ, you can focus directly on
the target plane. The four spots then merge into a single spot. When
working with higher energies, you must use anterior or posterior
defocusing, depending on the individual situation (
defocusing, page 56).
Where there is astigmatic distortion, the aiming beam spot pattern will
take on a different appearance, usually exhibiting rhombic distortion.
In this case, it is not always possible to merge the four aiming beam
spots when focusing on the target plane. From this it should be clear,
that in some circumstances it may no longer be possible to achieve the
desired effect at low energy levels, as the therapy beam will be similarly
distorted. It may be necessary to use a higher energy level in order to
achieve the desired effect. Return to a normal energy level when a
square aiming beam pattern is seen and it is possible to merge the four
aiming beam spots.
Note
Always work with the lowest energy possible.
Intraocular lenses made of silicone are considerably more sensitive than
intraocular lenses made of PMMA. For this reason, you should be
particularly careful when working with silicone lenses.
The aiming beam spot pattern may also be distorted if the contact lens
is held at too much of an angle. You should therefore avoid holding
the contact lens at too much of an angle for the purpose of minimising
reflections.
Warning
Never fire the laser if you cannot clearly see the aiming beam spot in
the target area.
000000-1354-664 VISULAS YAG III 15.08.2005
Operation
Focus exactly Focus posterior
on tissue to tissue
Focus shift and
Focus exactly
on tissue
Fig. 35 Distorted aiming beam
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