Keratoconus scan comparison

About this calculator

Enter Kmax and thinnest corneal thickness from two scans on the same device to see how each changed.

What you need

• The date, Kmax and thinnest thickness from each scan
• Both scans from the same device and protocol
• Whether you wore rigid, hybrid or scleral lenses before either scan

How it is calculated

Each change is later − earlier, shown with its own unit: diopters (D) for Kmax and micrometres (µm) for thinnest corneal thickness. No staging or progression rule is applied.

What the result can and cannot tell you

A change between two scans does not by itself show that keratoconus is progressing. Your cornea specialist looks for changes that repeat across the whole examination and imaging. Rigid, hybrid and scleral contact lenses can change the shape of the cornea for days to weeks.

References

1. Gomes and colleagues: Global consensus on keratoconus and ectatic diseases. Cornea 2015
2. Netra Eye Institute: Keratoconus

Related

• Endothelial cell change
• Corneal pain and light sensitivity diary
• Keratoconus guide
• All eye calculators

For information only. These tools explain numbers and do not replace an eye examination or your eye doctor’s advice. Values you enter stay in your browser.