Pachymetry

Pachymetric data can be used in OKULIX if a Tomey pachymeter is directly connected via cable. This is possible with the TMS-workstation as as well as with the PC-version without topographer.

Figure 39: Pachymetry

Upper image: geometrical arrangement of measuring points, lower image: result, with input window for corneal diameter ("white to white"). High accuracy is neither required for the measuring positions nor for the corneal diameter. In the example, the measuring values show a high variation of up to 200μm from center to margin, corresponding to an assumed corneal ablation depth of the same size, however, this results in a refraction difference of only 0.37D for a mean-sized eye with corneal diameter of 12mm. If this is increased to 14mm, the refraction difference decreases to 0.22D, but increases to 0.62D for 10mm corneal diameter. For a spatially constant corneal thickness, the refraction difference of course is always zero.