OCULUS Easygraph 70620 Instruction Manual page 24

Page 24
Ast: Astigmatism in the center of the cornea.
Axs: Axis of the astigmatism
Ecc: Mean eccentricity of the cornea
Øcor: Diameter of cornea (iris)
AA: Analysed Area. Gives the area of the
corneal surface actually measured (as
opposed to merely interpolated) as a
percentage of the entire measuring field.
• Numeric Display of Peak Values
(at the lower right) permits a rapid numeric
analysis of corneal topography.
The maximum and minimum radii of curvature of
several rings on the cornea (diameters of 3mm, 5
mm and 7 mm) are ascertained. These extreme
values are displayed
fashion, so that the magnitude of astigmatism and
its angle position are easily discernible.
Maximum curvature values are shown in red,
minimum curvature values in blue.
Note: ⇒ The major meridians are displayed if 4
peak values are not present on a ring.
• Finding Curvature Values
Clicking any location in the colored topographic
image causes the curvature values for that
location to appear above the mouse pointer.
Curvature corresponds to the parameters in the
color bar (mm/D, Sag/Tan, Rel/Abs).
• Field for Comments
At the top edge of the camera image is a place
for adding comments. For this purpose, click on the
top edge of the camera image with the mouse
pointer. Then a window appears saying "Change
info text", in which you can enter your comment or
change one already entered. Clicking the [OK]
button closes the window again, whereupon the
comment appears in the camera image.
This comment is also shown when the examinations
are loaded (cf. 7.5.5.1 page 70).
Instruction Manual Easygraph
in position-dependent
• Manual Measuring Function
This function allows you to measure the distance
between two arbitrary points in the camera image:
Clicking anywhere in the camera image (left mouse
button) automatically turns the mouse pointer into a
cross. By keeping the mouse button depressed you
can now position this cross in the camera image
with precision. After letting go of the mouse button
to mark a point of your choice you can position the
cross once more. In addition to the cross the system
now shows the distance to the first point and a
"rubber band" connecting line between the two.
Press the left mouse button once more to quit the
function. To delete measurement arrows generated
in this way, reselect " Display/Overview ".