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8
Troubleshooting
Examples of retinal photograph
Dark shadow or bright reflection ap-
pears at the top or bottom of the im-
age.
Dark shadow or bright reflection
appears at the left or right of the im-
age.
Peripheral area become whitened.
The image is dark.
The image is out of focus or blurred.
The center of the image becomes
whitened locally.
The lower area becomes whitened.
27
Possible cause
The objective lens is posi-
tioned too high to the pa-
tient's eye.
The objective lens is posi-
tioned too low to the patient's
eye.
The instrument is positioned
too far to the right or left to
the patient's eye.
Diopter compensation knob
is not at the click position.
The instrument is positioned
too close to the patient's eye.
The instrument is positioned
too far from the patient's eye.
The pupil diameter is small.
The patient has developed a
cataract.
The corneal surface is dry.
The objective lens is dirty.
The eyelid or eyelashes in-
trude the imaging area.
Remedies
Perform all alignment steps to obtain a clear
retinal image with consistent brightness. De-
pending on the patient's eye fixation condi-
tion, you may obtain a good image by locating
working dots away from the dot position aid.
Perform all alignment steps to obtain a clear
retinal image with consistent brightness. De-
pending on the patient's eye fixation condi-
tion, you may obtain a good image by locating
working dots away from the dot position aid.
Check that the diopter compensation knob is in
the correct position by slowly moving the knob
to see if it clicks.
Locate the optical component to the position
where working dots become smallest. If flare
still persists, pull the optical component a little
or move the optical component to the patient.
(Working dots may be fades a little.)
Turn the flash intensity control knob to +1 or
+2 position. If the patient's pupil diameter is
equal to or smaller than that shown by the
working dots, press SP button and photo-
graph in SP.
Avoiding the area of white turbidity during
alignment may allow you to obtain a good im-
age.
Ask the patient to blink before photographing.
Clean the objective lens.
Refer to "10. Maintenance and Inspection"
for details of the objective lens cleaning.
Ask the patient to open his/her eyes wider so
that the eyelid or eyelashes do not intrude the
area of the pupil. You or your assistant might
help the patient to keep the eye wide open.
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