Zeiss AT 030 Product Documentation Set page 33

Instruction for use
AT 030
319300-9120-000-GA-GB-240320
3. Pull the extensible measuring arm with measuring prism holder
up to the upper end position and then rotate it by 90° towards
the patient's side. The upper end position is reached after
overcoming a slight resistance.
4. Position the applanation tonometer in the beam path. Set the
rotary knob of the graduated drum to scale reading 1 so that
the measuring prism is in its front end position.
5. Swivel the slit projector about 60° to the side. Open the slit
completely and switch the blue filter on. Swivel in the optional
yellow filter to observe the measuring pattern with improved
contrast.
Observe the measurement through the selected eyepiece at a
medium magnification (e.g. 12x or 16x).
6. Ask the patient to open his/her eyes wide. You can assist by
splaying out the patient's eyelid with thumb and forefinger.
Take care, however, not to exert inadvertent pressure on the
bulbus. The fingers should rest only on the bony eye socket.
7. Adjust the measuring prism using the joystick of the slit lamp
vertically and horizontally to the patient's eye.
NOTE! The axis of the measuring prism is set at an angle of
approx. 6° to the axis of the slit lamp. Ask the patient to
look towards the measuring prism so that the measuring
prism can touch the corneal vertex centrally.
Figure 6: Measuring patterns produced by the applanation tonometer
8. Vary the measuring force by turning the rotary knob of the
graduated drum until the inner edges of the green semicircles
touch each other. The two semicircles must be of equal size,
and pulsate uniformly. In this setting, the applanation surface
has the nominal diameter of 3.06 mm. If the measuring force
has been set too high, a different pattern appears, as in Figure
c. If the measuring force has been set too low, the pattern will
be as in Figure a.
9. Multiplied by 10, the value read directly from the scale of the
graduated drum gives the intraocular pressure in mm Hg (see
Conversion table for tonometer readings [} 28]).
5 Daily startup
5.5 Measurement with AT 030
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