OCT macular thickness change

About this calculator

Enter the central subfield thickness from two OCT reports to see how much it changed, in micrometres and as a percentage.

What you need

• The date and central subfield thickness (CST or CSFT) of the earlier and later scans
• Both scans from the same device and scan protocol

How it is calculated

Change = later − earlier thickness. Percentage change = 100 × change ÷ earlier thickness. Days between scans are counted from the two dates. Values are rounded only for display.

What the result can and cannot tell you

Thickness is one feature of the scan. What it means depends on fluid, swelling, thinning, traction and the other retinal layers, and vision can change differently from thickness. Thickness numbers from different devices are not directly comparable. Your eye doctor interprets the scan as a whole.

References

1. Netra Eye Institute: Central subfield thickness and its clinical significance
2. Platform-independent Cirrus and Spectralis thickness measurements in diabetic macular edema

Related

• Amsler grid self-check
• Geographic atrophy growth
• Ellipsoid zone width change
• Macular thickness 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.