OCULUS Pentacam Interpretation Guide

15
5 Differences between Placido and
elevation-derived curvature maps
by Prof. Michael W. Belin
5.1 Keratoconus in OD and OS?
The case shown below explains the difference between suspicious and significant elevation maps
and numbers. The topographic map (Figure 8) shows the left and right eye but gives no unequivocal
statement if it is a keratoconus or not.
The right eye seems to be fine. The left eye is a little steeper. The Pentacam® 4 Maps Selectable
answers clearly the question.
Figure 8: Placido based topography of OD and OS allowing no conclusion regarding
keratoconus
5 Differences between Placido and
elevation-derived curvature maps

OCULUS Pentacam Specifications

General

Measurement Time	Less than 2 seconds
Corneal Coverage	Up to 12 mm
Software	Pentacam Software
Data Transfer	USB
Corneal Topography	Yes
Display	External monitor required
Measurement Principle	Scheimpflug imaging
Camera	Rotating Scheimpflug camera
Light Source	Blue LED
Pachymetry	Yes
Anterior Chamber Analysis	Yes
Imaging Principle	Scheimpflug imaging
Fixation	Internal
Power Supply	100-240 V, 50/60 Hz
Resolution	High resolution
Lens Density Measurement	Yes
Dimensions	Varies depending on model and configuration
Weight	Varies by model, check manufacturer specifications
Number of Images	25 or 50