confrontation tests Flashcards
what is the purpose of confrontation tests?
relatively gross technique to screen for presence of visual field defects.
what are some indications for the test?
GROSS screening test that is part of routine comprehensive eye examination
Useful in patients where automated perimetry is NOT possible such as bedridden patients, children
what are some advantages of CF test?
Simple test to perform
Quick
Does NOT require any special instruments or equipment
good for home visits as they are portable
inexpensive compared to automated perimeters
what are some disadvantages of CF test?
Only able to detect MASSIVE defects
May not be used for monitoring purposes
Too much inter-examiners variability : NO consensus on STANDARD procedures
what are the 4 set up steps for CF?
The examiner must be sitting at the same height as the patient
Occlude the patient’s LE
Testing distance = 60 cm
During Facial Amsler (FA), patient should be wearing their fully corrected rx.
However, when testing the peripheral vision, it is advisable to remove the spectacles as some of the spectacle’s frame can block the vision.
what are the 3 steps and instructions for Facial amsler?
Occlude the patient’s eye
Ask the patient
“Can you see my nose?”
“While looking at my nose, is there any part of my face appears distorted to you?”
what are the 4 steps and instructions for central finger counting?
Now, ask the patient to keep looking at your opening eye
Present your fingers in each of the 4 quadrants
only test ONE quadrant at a time
Ask the patient:
“How many fingers do you see?”
what are the 4 steps and instructions for simultaneous finger counting?
Still looking fixating at your opening eye
Now, present 2 targets in the 2 upper quadrants simultaneously
Ask the patient
“How many fingers in total do you see?”
Repeat the above in 2 lower quadrants
what are the 3 steps and instructions for simultaneous hand comparison?
The examiner presents his hands with palms facing himself, side by side on each side of the vertical imaginary line
Ask patient
“As you are looking at my opening eye, is one hand clearer or brighter than the other or are they about the same?”
Repeat on top and bottom on each side of the horizontal imaginary line
what are the 2 steps and instructions for peripheral finger counting?
Similar to FC but now the fingers are shown as far out as possible
Ask the patient
“Still looking at my opening eye, how many fingers am I showing?”
what will be the recording for normal ?
OD & OS: Full to (FA, FC, SFC, SHC, PFC)
what will be the recording for abnormal ?
For VF defects,
Put a tick (√) in the quadrant seen and a cross (X) in the quadrant not seen.
Describe the purpose for each step of the confrontation fields (FA, FC, SFC, SHC, PFC)
- FA: central scotomas and scotomas in central field
- FC: detects presence of absolute scotomas in central fields
- SFC: detects extinction phenomenon which may be present in Parietal lobe lesions
- SHC: check for relative hemianopia, check for relative quadranopias, altitudinal hemianopia and nasal steps. Mainly for glaucoma but it is hard to pick up
- PFC: compares examiner’s VF and px VF
