Confrontation testing is a simple preliminary test to screen for peripheral visual field defects. It does not require any equipment and can be done anywhere. The examiner positions their face about a meter in front of the patient. While the patient fixes their gaze on the examiner's eye, the examiner moves their finger in an arc from the periphery towards the center to test each half of the visual field. Any areas that the patient cannot see the finger represent potential visual field defects. While quick to perform, confrontation testing has limitations as some mild or moderate defects may be missed, and it is subjective in nature. Further visual field testing is needed to confirm any defects found.
2. confrontation test is one of the simple,preliminary test which
is done for gross visual field(peripheral) screening both
monicularly and binoculary.
it falls under kinetic perimetry.
confrontation testing is best viewed as a pass/fail test as the
results are quantative.
No equiptment is necessary; it can be done anytime or
anyplace.
principle used in this test is that the field of vision of
INTRODUCTION.
4. procedure contd;
prior to testing of visual field insure central vision and
visual acuity is intact.
Initially,position yourself in front of the patient facing
her/him with your face level , at a distance of about a
metre(variable).
With the examiner seated directly across from the pt,the pt
should direct their gaze to the corresponding eye of the
examiner without the movement of head.
For examining right eye,instruct patient to cover their left
eye and fixate the gaze at examiner’s right eye,at the same
time you as the examiner close your right eye and viceversa.
5. prodedure contd;
with the patient fixating the examiner’s eye,the test object
or a finger is moved in a flat plane midway between the
patient and examiner from the periphery in an arc
stimulating the curve of an imaginary perimeter as far as
possible .
The patient is instructed to report when he or she first sees
the object.the test is usually done in 8 half
meridians(0,45,90,135,180,225,270,315 degrees).
Two test object can be used simultaneously ,one in
temporal field and one in the nasal field.This technique is
valuable in detecting hemianopic field defects that might
otherwise be easily missed.
6. prodedure contd;
Harrington refers to this process as the extinction
phenomenon:the presence of the stimulus in the seeing
field gives the impression of “extinguishing” the test
object in the nonseeing field.
first test the binocular field and then test each eye
separately a defect is detected by the absence of a
patient response to the showing target,when the target
is visible to you.
The process should be repeated in each quadrants for
each eye separately and establish the boundaries.
8. ●If we are able to stretch to test the limits of the patient's
field, then we are no longer comparing the patient's visual
field to our visual field.
13. The test distance(d) should depend on the purpose of the
test;if the examiners desires to test the temporal field of 60
degree,then a distance of 60 cm would be
necessary.Algrebrically
cos 60 = b/h
½ =
or,½ = d/2y
:y = d.(hence,for 60 degrees evaluation distance between
patient and examiner would be equal to test distance, and most
people have arm length less than 70 com so 60 cm would be
ideal).
If someone performs this test using 100cm between examiner and
d/2
y
b=d/2
14. interpretations of confrontation test:
A comparision of examiner and patient’s fields is made,the
assumption being that you,as the examiner have normal visual
field.
If the patient cant see the object when it is visible to you then it is
interpretated that patient may have visual field defect.
If defect is detected ,re-examine that area and define it further.
Any discrepancies between the examiner’s and patient’s visual
field after repetations then should prompt further field
examinations.
With a suitable test object,the examiner can outline the patient’s
blind spot ,demonstrating what is meant by the disapperance of
19. Drawbacks of confrontation test.
Drawbacks of this approach alone is that early(or even moderate)
visual field defect often go unnoticed ,particularly if one eye is
affected.
It is a subjective test and sometimes misinterpretations of report
may be presented if the patient has poor compliance, usually
pediatric and geratric patients.
It is the screening test and the diagnosis can’t be made alone
with this test.