13.5.2 Further adjustments for the anterior chamber depth
Caution should be practised when using the device’s ACD measurement for any given intraocular lens
calculation because of the high variability of this measurement.
The ACD measurement is the distance between corneal epithelium and the crystalline lens surface.
At the end of the automatic acquisition of K-values and axial length, ACD must be acquired manually following
the alignment procedure.
Figure 35
The slit is turned on, and the central alignment of the slit on the corneal apex can be performed.
Follow the instructions of the red and blue arrows until optimum acquisition conditions have been reached
and the software will automatically capture the image for the measurement.
13.6 Acquisition of axial length measurements (AL)
Interpretation of axial length measurements
As a rule, an interference signal is produced if the measuring light is reflected by the retinal pigmented
epithelium of the eye. This signal is utilized for axial length measurements.
Note: Ultrasonic biometrical instruments measure the axial length as the distance between the cornea and
the inner limiting membrane, because the sound waves are reflected at this membrane. To ensure that the
measured values obtained with the Aladdin are compatible with those obtained through acoustic axial length
measurement, the system automatically adjusts for the distance difference between the inner limiting
To Next Page
Loading...
