Changing The Scale Of The Fluo Image; Top Test - OCULUS Easygraph 70620 Instruction Manual

To change the scale of the fluo image, click on the
green color bar in the left margin of the fluo image.
This produces a window in which you can change the
maximum value of the scale. The default value is 100
(µm). If a different scale has been selected, this is
indicated by the remark "!!Scale!!" next to the scale.
The "Display" field in the Contact lens fitting window
can be switched to "Top Test":
This presentation mode lists the individual meridian
angles (Mer.), the central radius of the meridian (r0),
the coaxial radius at 30° (rs), the degree of flattening,
i.e. the difference between central and coaxial radius
Instruction Manual Easygraph

7.5.3.2.4 Changing the Scale of the Fluo Image

7.5.3.2.5 Top Test

Changing the scale can be helpful in cases of, for
example, marked keratoconus, as a larger maximum
value (e.g. 300 µm) makes it possible to assess
distance curves involving large distances (i.e. in
cases of poor lens fit).
Changes of scale are automatically followed by a
recalculation of the fluo image.
= • + •
p k 1 ( c 1 k )
2
h
=
k
where:
•
2 r 0
p
p =arrow height
h =zone height
h
r0 =central radius
r0
(rs-r0), the resultant eccentricity at 30° (Ecc) and the
flattening constant (c1).
In conjunction with the central radius r0 the flattering
constant c1 permits a mathematical description of the
corneal paraboloid.
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