Essilor MYOPIA EXPERT 700, Руководство пользователя

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
Curvature Irregularity: Irregularity of curvature calculated on the standard deviation of the
instantaneous readings for a 4.5mm diameter cornea area

Asymmetry + SAI: Asymmetry between the most curved hemisphere and the flattest one,
calculated for a 4.5mm diameter cornea area and a SAI (Surface Asymmetry Index), which
represents the surface asymmetry index of the 4.5mm diameter cornea area.
Corneal asphericity
The window is composed of two tabs (Asphericity and Peripheral degrees), which specify the corneal
asphericity.
The Corneal Asphericity window could also be invoked from the Corneal Height Map environments. In this
case, as in the topographic map, the user should choose the Asphericity Corneal menu item.
Asphericity
Fig. 30
As you can see from Fig.30, the panel is divided into four parts.
The top-left rectangle (Principal meridian asphericity (8mm)) contains three rows:

In the first row you can read the apical radius (Ro) and the asphericity (e) along the flattest
meridian (@);

In the second row, there are the same parameters calculated along the steepest meridian; in the
third row, there are the average values of the apical radius and the asphericity. The parameter
calculations are based on a circular area centered in the center of the rings with diameter= 8mm.