Your Date with Mr. Humphrey
KEY # 1: INSTRUCTIONS
How can you expect to get a quality test if you don't tell the patient what you want them to do? Patient Instruction is critical.
Following are bullet pointed instructions. I recommend you post them to the left side of your visual field screen so you can easily glance at them while instructing the patient.
PATIENT INSTRUCTIONS
Test of side vision
Makes a map of vision
Chin in chin rest, forehead against bar
Look straight ahead at yellow light. Do not look away from the yellow light
You’ll see flashing lights. Some will be very bright, some very dim
Sometimes you won’t see a light for a short time - that’s normal
Push button whenever you see any light other than the yellow light
Keep chin in chin rest, forehead against bar
Do not move your head
Blink whenever you want
Remember to only look at the yellow light and push the button whenever you see any light other than the yellow light
INSTRUCTIONS FOR THE VISUAL FIELD TECHNICIAN
This test requires a partnership between the patient and the technician therefore, it's equally important the technician also knows what to do. Following are bullet pointed instructions for the technician:
Place lens(es) in lens holder
If possible, align handle of lens supero-temporally
Patch eye not being tested
Confirm patient cannot see around patch
Give patient response button
Position patient
Height of table ok for pt?
Chin on chin rest
Teeth together
Forehead against bar
No head tilt or turn
“Can you see the yellow light in the center?”
If no, change fixation target small or large diamond target. Pt should fixate in middle of diamond
Align pupil in cross hairs on monitor screen
KEEP CROSS HAIRS CENTERED IN PUPIL THROUGHOUT TEST
DURING THE TEST
“Push the button whenever you see any light other than the yellow light”
Encourage patient but don't distract from test
You’re doing great
You’re almost done
For Fixation Losses
Remind patient to look only at yellow light
Is fellow eye fully patched?
Click ‘Retry to find blind spot”
Recheck patient's head and eye position
Goal: < 20% fixation losses
KEY # 2: PATIENT POSITIONING
If you're not sure how to fix a positioning problem, ask the patient to sit back, pull the patient's chair back and start from scratch with positioning the patient. Here are the important points:
Chin down, teeth together
Forehead against bar
Lens as close to eye as possible without eyelashes touching lens
Head straight (no tilt or turn)
The patient's chair should be aligned straight with the chin rest/VF machine
Pupil aligned in cross hairs
Yes, Visual Field Testing can be boring and arduous for the technician and for the patient, but if you carefully instruct your patient and closely observe the patient's positioning, you will be much more likely to obtain an accurate, quality test. Your patient AND doctor will appreciate your efforts.