OCULUS Pentacam - Proposed Screening Parameters

48
10 Screening for refractive surgery
10.1.2 Proposed screening parameters
It is essential to check the settings for the fitting zone of the BFS in the settings of the Pentacam®,
since this influences the borderline numbers (Figure 57).
 If you are using the manual (fixed) 9 mm zone for fitting the BFS, the proposed screening
parameters I use are:
In the anterior elevation map differences between the BFS and the corneal contour less than
+12 μm are considered normal, while differences between +12 μm and +15 μm are suspicious,
and differences > 15 μm are typically indicative of keratoconus. Similar numbers about 5 μm
higher apply to posterior elevation maps
 If you are using the manual (fixed) 8 mm zone for fitting the BFS, the proposed screening
parameters I use are:
Anterior elevation differences less than 8 μm are considered in the normal range, while
differences > 8 μm are typically indicative of keratoconus or other ectatic disorders (in the
central zone). Posterior elevation differences < 11 μm are considered in the normal range,
while differences >16 μm are suspicious
Figure 57: BFS fitting zone