CORNEAL TOPOGRAPHY

Pentacam uses the Scheimpflug principle to obtain sectional slice images of the cornea In Pentacam, the Scheimpflug camera rotates 180 degrees around a single fixation point while the patient focuses a central light source. By rotating around the fixation point, it reduces artefacts created by small movements during image acquisition.

The pentacam produces elevation-based topography, which offers significant advances over Placido-based devices. The ability to see the posterior cornea and produce an accurate pachymetric map is in itself significant. Elevation maps are also more accurate for determining cone morphology and for separating false positives suspected of keratoconus, often due to a displaced corneal apex.

In short, they provide greater certainty when assessing a patient for refractive surgery.