65
4-4-6 Retroillumination Mode
In the case of “the measured value varies”, “the confidence value is low”, etc., there may be
foreign substances that obstruct measurement light such as opacity of the lens. For such
patients, you can observe the optic media by using “Retroillumination mode”.
1.
Push
to shift to retroillumination mode.
2.
Mire ring and background illumination (light illuminating the outer eye part such as the
iris) lights. Then, position the patient eye to central.
3.
Press the measurement switch, only measurement light is lighting and mire ring and
background illumination are light out, only the central cornea reflected light and pupil
can be seen. Any foreign objects, such as opacity in the crystal lens, that obstruct the
measuring beam, appear as black shades on the screen.
Observation of optical media by retroillumination mode
•
A better view may results by shifting the image off center. In particular, an opacity
existing in the center can only be seen by projecting light off the opacity.
•
Do not expose the patient’s eye to external light (such as illumination from a
fluorescent tube) as that may lead to deterioration of visibility.
4.
Press the measurement switch to restore the condition given Step 2.
5.
Push
again to return the measurement standby mode.
