IOLMaster — Axial Length Measurements
Valid Signal Curves
ALM Signal Curves.
- Very good signals (signal-to-noise ratio > 10)
- Several secondary maxima visible (system specific)
- Clear media, correctly fixating patient
- Slight ametropia
- Clear signal (SNR display GREEN)
- Secondary maxima visible
- Relatively clear media
- Signal in "Borderline SNR" (uncertain) range (SNR display YELLOW)
- Steep rise of measuring signal
- Such readings are marked on the display by an exclamation mark
and the message "Borderline SNR" (uncertain reading)
This reading may be used after verification and comparison with other
data from this series of measurements.
Maladjustments on the Graph
- Low signal (SNR display RED)
- Error message is displayed.
- The measuring signal cannot be clearly distinguished from the
- Unsteady (non fixating) patient
- Strong ametropia
- Dense medial opacity along the visual axis
Repeat the measurement!
Ask the patient to fixate steadily.