Zeiss AT 030, Product Documentation Set

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Instruction for use 8 Troubleshooting
AT 030 ​
319300-9120-000-GA-GB-240320 47 / 60
8 Troubleshooting
Action 1. The axis of the measuring prism must coincide with the normal
to the corneal surface. This is the case if the fluorescein
semicircles are symmetrical to the separating line.
The two fluorescein semicircles are visible in the center of the
eyepiece and touch each other at their inner edges.
Figure 14: Correct measuring pattern
2. If this condition is not met, patterns as shown in the following
figure will appear. These patterns require the slit lamp and thus
the measuring prism to be repositioned laterally and vertically.
Figure 15: Measuring patterns requiring correction of the tonometer
position
Possible faults and their remedies are described below.
Fault Eyepiece
image Remedy
Fluorescein ring too wide/too small
Fluorescein ring too wide:
The measuring prism was not dried
after cleaning or the eyelids
touched the measuring prism
during measurement. In this case,
the reading is higher than the
actual pressure. Pull the slit lamp
back and dry the
measuring prism
with a lint-free
cloth (e.g. made
from cellulose)