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Indiana University Bloomington

Classification of Keratoconus

Keratometer Readings

Keratoconus has been classified in a number of ways. One method is by the keratometer readings as follows:

The unit "D" is diopters, or units of corneal power.
Classification Keratometer Readings
Mild <45.00D
Moderate 45.00 to 52.00D
Advanced 52.00 to 62.00D
Severe >62.00D

Morphological Shape

Another method (or in combination with the above) is to use the morphological shape:

With the availability of corneal topographers a more quantitative description is possible and results in a more accurate description where the actual position of the cone (axis and distance) from the visual axis can be given as well as the dioptric power at the peak of the cone.
Shape Example
Round or Nipple unavailable
Oval or Sagging
Ill-defined unavailable