Tomey TMS-5, Инструкция по эксплуатации

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3-60
refractive powers measured on the cornea.
When the distribution range of corneal refractive
powers is large, the value becomes large.
The CVP value may be large soon after corneal
transplantation or in the case of severe keratoconus.
● ACP (Average Corneal Power)
The ACP represents the average refractive power within
the pupil diameter. The ACP value is normally equal to
the spherical degree for measurement of the corneal
curvature. Therefore, this value becomes abnormal
for the same reasons as in the case of measurement
of corneal curvature, except for the refractive power
correction surgery due to misalignment of the center.
● SDP (Standard Deviation of Corneal Power)
The SDP is calculated by distribution of the refractive
power of all measurement points on the cornea.
The SDP value often becomes large in the case of
keratoconus, corneal transplantation, external injuries,
and when the refractive power range is large.
● CEI (Corneal Eccentricity Index)
The CEI is calculated as a factor of the corneal shape,
based on the eccentricity of an ellipse. Positive values
represent a prolate shape where the surrounding
area is flat. “0” means a sphere and negative values
represent an oblate shape where the surrounding area
is steep.
It is assumed that values outside the acceptable range
represent keratoconus (larger than the normal value)
and that negative values represent eyes with contact
lenses or a refractive power correction operation for
myopia.
● IAI (Irregular Astigmatism Index)
The IAI sums the fluctuations of the refractive powers
on each ring for each meridian on the entire cornea
and shows the average value (irregular astigmatism