PDR-7000 Operation Manual
4.5.5 Von Graefe test (horizontal phoria)
Use: To detect horizontal phoria
Chart: Vertical line
Auxiliary lens: 6ΔBU to the right eye, rotary prism to the left eye
Applicable model: PACP-7000, PACP-7000L, PLC-7000, PLC-7000pola,
PLC-7100, PLC-7100pola, PLC-8000, PLC-8000pola
[For the other types, use the highest VA letter chart or the letter
chart which is little higher than the patient’s VA.]
Ideal appearance:
Right eye Left eye Binocular ideal
[Procedure example]
1. Present the vertical line chart.
Press .
6ΔBU is placed in the right measuring window.
The base in/out prism powers can be entered.
1. Press to occlude the left measuring window.
2. Press to open the left measuring window.
3. Ask the patient, “Can you see two circles with a column of letters in each of
them? Do the letters line-up, like buttons on a shirt?”
When they are not in line, correct them so that they appear in line at the instant the
occluder is removed. (Use the Flashing Technique as shown in Steps 2 and 3.)
Appearance of chart Phoria Correction
The upper column is on the left.
Esophoria
Turn the dial clockwise to add the BO prism
powers until the two columns line up.
The upper column is on the right.
Exophoria
Turn the dial counterclockwise to add the BI
prism powers until the two columns line up.
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