2. What is Suppression??
• Suppression is active but unconscious and
involuntary inhibition of vision in one eye
• Present under conditions of binocular
viewing
• Occurs as diplopia occurs
3. Antisuppression Therapy
• Anyone who has undergone therapy for
ARC or Amblyopia has already had some
therapy for suppression
• This involves using first degree fusion
targets
• Once patient can superimpose targets with
NRC, Antisuppression therapy can
begin
5. Goals of Suppression Treatment
• Make patient aware of diplopia
• This diplopia needs to be appreciated with
one eye deviating
• Make patient hold fixation with either eye
always seeing the blurred image
6. Contd..
• Establish sensory fusion and proper retinal
correspondence
• Then stabilize sensory fusion
• Then improve motor fusion
7. Treatment of Suppression
• Treat if any strabismus
• Proper refractive error correction
• Allignment of visual axis- to permit
simultaneous stimulation of corressponding
retinal element by same object
8. Contd..
• Occlusion therapy in case to overcome
amblyopia
• Antisuppression orthoptic exercise before or
after surgical therapy of strabismus
9. When breaking down Suppression
consider the following
• Brightness
• Target Size
• Intermittent Stimuli
• Target Movement
• Target Contrast
• Color
• Tactile and Kinesthetic Senses
• Auditory Sense
10. Brightness
• Brighter target easy for suppressing eye to
see
• Always put brighter target in front of
suppressing eye
• Deeper suppression larger difference in
brightness of the two targets
11. Target Size
• Targets used in antisuppression training
should be larger than suppression scotoma
• Target becomes smaller with therapy as the
scotoma shrinks
• Progress slows once foveal antisuppression
begins because this is most difficult to
eliminate
13. Target Movement
• By moving the target non corressponding
points are stimulated and these are less
likely to be suppressed
• Also by moving the target you keep the
patients attention making suppression of
image less likely
14. Target Contrast
• More contrast between background and
foreground in target less likely target will be
suppressed
• Thus suppression is difficult to break under
natural conditions because the contrast is
low
15. Color
• Color targets need to be used because
• More interesting to patients
• And are more difficult to suppress than
black and white targets
16. Auditory Sense
• Some devices such as Eye Hand coordinator
use buzzers through which he/she can be
aware if doing the exercises incorrectly
• Sound provides immediate feedback
• Motivates the patient and improvement
occurs as the suppression is broken
17. Antisuppression Therapies
• Cheiroscope
• Tube and Hand
• Brock String
• Chiastopic Training
• Bar Reader
• Vectograms
• Tranaglyphs
• Brewster Stereoscope
• Modified Brock Posture Board
18. Brock String And Beads
• This is an outstanding therapy because of diplopia
awareness and fixation accuracy
• Brock String is inexpensive and an easy home
therapy
• Teaches patient how to aim eyes together correctly
for varying distances
• It allows the patient to determine if she/he is
shutting of an eye or suppressing
• This is usually first technique patient is taught and
is often given as home therapy
19.
20. Procedure
• Place one end of string on tip of your nose
• Nearest bead app 10 inches away middle bead 20
inch and farthest bead 30 inch away
• Look at middle bead, you can be aware 2strings
farther and 2strings closer and the farthest and
nearest bead appeared double
• Similarly keep looking at the farthest bead and
also at nearest bead
• Wear any special lenses and prisms that were
prescribed and they may change as therapy
progresses
21. “Tube and Hand”
• Also known as “Hole in Hand”
• Simple and effective antisuppression therapy
option for preschoolers
• Patient holds cardboard tube before one eye and
holds his hand in front of other eye
• Patient should see both the circle and the hand
simultaneously
• If doesn’t means he/she is suppressing one eye so
need to teach him
22. Cheiroscope
• Cheiroscope is drawing exercise and should not be
used on patient with ARC because it will reinforce
it
• It is used to assess binocular stability and to detect
the presence and extent of suppression
• Training on it gives patient important feedback
that he is suppressing the eye and gives him an
opportunity to gain binocular control necessary to
eliminate his suppression
24. Procedure
• Dominant eye fixates a simple picture through a
mirror
• Non Dominant eye views a blank piece of paper,
onto which the patient copies the picture seen by
the other eye
• Examiner must watch the patient to make sure
he/she does not alternately fixate which can be
monitored by using a mirror that also changes the
picture's size
• If the drawn picture is the same size as the
original, the patient is alternately fixating
25. Bar Reader
• The Bar Reader, or
reading with a physical
anaglyphic or polarized
septum between the
patient and the material
• It must be used for those
with no strabismus
because alignment is
necessary for the patient
to read
26. Chiastopic Training
• It is done by voluntarily crossing (i.e.,
converging) the eyes to fuse two objects
held out in front of the patient
• The targets can be pencils, fingers/thumbs,
eccentric circles, or any other paired items
• It is a difficult skill that may discourage the
patient
• Do not use this technique early in therapy
27.
28. Vectogram
• Vectograms with 'suppression checks' and
various sizes of targets are an excellent
option for therapy
• The patient wears polarized lenses over any
prescription glasses
• Parts of the pictures are missing if the
patient suppresses
29.
30. Tranaglyphs
• Tranaglyphs, or targets used with red-green
glasses, are similar to vectograms
• They come in different sizes and in various
amount of detail with suppression cues
31. Procedure
• Is done with a slide of alternating red and green
bars that is placed over reading material or over
the TV screen
• While the patient wears red-green glasses
• Two full- or half-size sheets of red acetate and
green acetate can also be placed over the TV (or
computer) screen
• This method is also known as a "TV trainer" and
works great with video games
• If the patient suppresses, the whole picture is not
seen.
32. Contd..
• Other Tranaglyphic techniques can be
created using the same principles
• Another example of an anaglyphic anti-
suppression technique is Sherman's palying
cards, available from Bernell
• With these playing cards and red and green
glasses, the patient must be using both eyes
to see all of the cards
33.
34.
35. Stereoscope
• Stereoscope uses
stereograms as targets
for superimposition
• The patient needs to see
both targets, the dog and
pig with the
Telebinocular
• This can train at
distance and near
36. Modified Brock Posture Board
• It uses red-green spectacles, sheets of white
paper and red translucent plastic of identical
size, a penlight and red marker
• The patient draws lines on the white paper
with the red marker
• The paper is held beneath the red sheet with
one hand while the other holds the penlight
37. Contd..
• The patient then traces the lines with the
penlight and sees the red lines on white
paper with the left eye
• Only the right eye sees the penlight tracing
the lines (seen by the left eye) below the
paper
38. Amblyoscope
• The amblyoscope is a machine which trains a
child to use his/her eyes together
• The goal is to achieve binocular fusion, or normal
two-eyed, single vision with depth perception
• As the child progresses in skill therapist increases
the fusional demands to stretch and normalize the
patient's ability to efficiently use his/her two eyes
together
39. Contd..
• This machine also
allows a child to know
when he/she is
suppressing an eye
• Visual awareness is the
first step in successful
training
41. “Flippers”
• Lenses and prisms are always
important in visual training
• Here a child is working on a
focusing technique called
accommodative rock
• The "flippers" hold two
different sets of lenses
• One is a pair of plus lenses; the
other are minus
42. Contd..
• By rapidly alternating between the two sets of
lenses, the patient is forced to relax or stimulate
accommodation in order to clearly see the print
thus gaining greater facility and control over his
focusing
• Patients always begin with lower powered lenses
and gradually increase the strength at which they
can successfully complete the task
43. Push Up Test
• Eyes with conditions called Convergence
Insufficiency and Exotropia have difficulty
turning their eyes inward
• As a result, they often struggle because they
simply can't maintain the inward eye aim required
most close up activities
• These children have to be taught to converge their
eyes
44. Contd..
• Here a therapist is helping a
young patient experience
the "tug" she should feel on
both sides of her nose
bridge as muscles located
there contract and pull her
eyes inward
• Kinesthetic awareness is an
important first step in
teaching the child to control
her eye coordination
45. Saccadic Fixator
• The saccadic fixator is an instrument which
trains saccadic eye movements, tracking,
visual memory, peripheral awareness, and
visual motor integration
• It allows the children to set goals for
themselves as they continually strive to
improve their last performance
46. Contd..
• Besides children with
oculomotor dysfunctions, this
machine is particularly good
for young athletes; it
improves their eye-hand-
body coordination and
response time
• Overall, it's an excellent
trainer for visual stamina and
efficiency
47. Rotator
• The rotator is an instrument used to increase
a child's visual efficiency and stamina
• Used primarily to improve eye movements
the child is asked to place golf tees in a
rotating pegboard
• As the child's skill improves, the speed at
which the pegboard is rotating is gradually
increased
48. Contd..
• This procedure is
usually done while
the patient is wearing
a patch over one eye
• Strong monocular
("one-eyed") skills
must be gained before
a child can achieve
good binocular, two-
eyed skills