Amsler-Krumeich Staging (Keratoconus)
Amsler-Krumeich keratoconus classification (Krumeich 1998): stage 1-4 by the most advanced finding.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Mean central keratometry
- 50 D
- Thinnest corneal thickness
- 450 um
- Myopia + astigmatism
- 6 D
Result: Amsler-Krumeich stage 2 — moderate keratoconus.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Parameters
- mean K (<48/48-53/54-55/>55 D), thinnest thickness (>500/400-500/200-400/<200 um), myopia+astig (<5/5-8/8-10/>10 D), central scar (=stage 4).
- Stage
- the most advanced single parameter, 1 (mild) to 4 (advanced).
What you enter
- Mean central keratometry (diopters)
- Thinnest corneal thickness (microns)
- Myopia + astigmatism (diopters, optional)
- Central corneal scarring present (stage 4)
How this is calculated
Krumeich JH, Daniel J, Knulle A. Live-epikeratophakia for keratoconus. J Cataract Refract Surg. 1998;24(4):456-463. (Stage boundaries per Kamiya K, et al. Sci Rep. 2018;8:12852.) Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.