What does the Pentacam measure?

Explanation Pentacam

Early diagnosis is very important for the patient with keratoconus. The later the diagnosis, the worse the vision. The Pentacam measures the shape of the cornea in an advanced way, allowing keratoconus to be recognized at a very early stage. With special software, the progression of keratoconus can also be closely monitored.

The Pentacam measures:

1. The shape of the front of the cornea.
2. The shape of the back of the cornea.
3. Corneal thickness.

Below you can see an example of this:

The 4 images show four different measurements.

1. The first image on the upper left shows the topography of the front of the cornea.
2. The elevation front shows how much the cone extends above the normal shape of the cornea.
3. The elevation back shows how much the cone extends above the normal shape of the back of the cornea.
4. The corneal thickness shows the thickness of the cornea and the cone.

By combining these four measurements, keratoconus can be properly assessed for progression. Special software, the Belin/Ambrosio Display, makes analyzing these images even more complete. This allows ophthalmologists and optometrists to monitor the progression of keratoconus. After demonstrable progression, a patient is referred for treatment. This treatment is called Corneal Cross Linking (CCL/CXL).

Keratoconus progression is assessed on three different characteristics:

• Has the thickness decreased at the cone?
• Has the bulge and curvature at the back of the cone increased
• Has the bulge and curvature at the front of the cone increased

Progression should always be determined over the past year. When there has been too long a time between measurements, it is not clear whether the progression had occurred in the past year or before.

Since Corneal Cross Linking has the goal of stopping progression, it must be noted that progression has been active over the past year.