Essilor Medica 700, User Manual

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63
Wave Analyzer Medica 700 User Guide
63
Overview of the Software
*Formulas :
We use the following formula when P<1: ( P=1-e
2
) and (Q= P-1).
*Data taken from : "The Optical Quality of the Cornea", by Calossi A. (Fabiano Editore)
Italy; 2002:1-13.
p8 mm e8 mm
e
2
8 mm
Q 8 mm p
4 .5 mm e
4 .5 mm
e
2
4 .5 mm
Q 4 .5 mm
Mean 0.72 0.51 0.28 -0.28 0.86 0.31 0.14 -0.14
Std.
Dev 0.13 0.14 0.13 0.13 0.12 0.24 0.12 0.12
Min 0.14 -0.22 -0.05 -0.86 0.47 -0.46 -0.21 -0.53
Max 1.05 0.93 0.86 0.05 1.21 0.73 0.53 0.21
Here is data taken from study sample of 1030 eyes. It includes the mean values, standard deviation, and
range of apshericity. The data is relative to the anterior surface of the cornea on a diameter of 8mm and an
optic zone of 4.5mm
Keratoconus Table
The Keratoconus table displays the following data:
KPI: Index of the probability of keratoconus
CAUTION: Keratoconus indices are designed to be an adjunct to a clinical
examination, and should never be used as a sole assessment tool in the diagnosis
of Keratoconus.
Results of a clinical trial of the Keratoconus Prediction Index (KPI) are described in
reference 1 and more details of the mathematics are given in reference 2.
Reference 1. Calossi A. Le altimetrie corneali con sistemi a disco di Placido. In: Mularoni A, Tassinari G,
eds. La Topografia Altitudinale. Canelli, Italy: Fabiano Editore; 2005:136-139.
Reference 2. Maeda N, Klyce SD, Smolek MK, Thompson HW. Automated keratoconus
SI: Symmetry index - the difference between the mean power of two circular zones
centered in the vertical axis
AGC: Apical Gradient of Curvature - the mean variation per unit of length of the corneal
power between the corneal apex and the periphery of the keratoconus
AK: Apical Keratometry - the curvature of the corneal apex
Note: Values that are associated with a high probability of keratoconus are marked with an
asterisk, like the SI and AGC values in this example: