Anti-Suppression

Question 1

BV

Answer 1

Ability to integrate info from both eyes and extract depth info

Question 2

Eyes separated by ___ —> each eye has different view

Answer 2

~60 mm

Question 3

Sole basis for stereopsis

Answer 3

Horizontal disparity between the 2 retinas

Question 4

T/F: BV natural to most people

Answer 4

TRUE

Question 5

Fusion of 2 images / single BV requires

Answer 5

1. Adequate fxn of each eye
2. Sufficient stim to corresponding retinal points in the two eyes

Question 6

1st degree fusion

Answer 6

Simultaneous perception
Can see 2 dissimilar images (dog OD, house OS)

Question 7

2nd degree fusion

Answer 7

Flat Fusion
2 similar objects as one (Worth 4 Dot)

Question 8

3rd degree fusion

Answer 8

Stereopsis

Question 9

T/F: 1st degree fusion is considered a true fusion

Answer 9

FALSE; 1st degree = simultaneous perception (dissimilar objects)

Question 10

Visicare cards test what type of fusion?

Answer 10

2nd degree / flat fusion

Question 11

Keystone Visual Skills Fusion card (red/white/blue circles) test what type of fusion?

Answer 11

2nd degree = flat fusion

Question 12

What is the “barometer of BV”?

Answer 12

Stereopsis

Question 13

___ and ___ decrease stereopsis;

What sxs does this cause?

Answer 13

Suppression and excessive fixation disparity

Asthenopia + reduced visual performance

Question 14

What type of diplopia is normal and can be used as a tool for VT?

Answer 14

Physiological

Question 15

What type of diplopia is abnormal?

Answer 15

Pathological (aka Strab)

Question 16

Pt’s defense against diplopia

Answer 16

Suppression

Question 17

Suppression can only occur under ___ conditions and is attributed to ___.

Answer 17

Binocular viewing
Cortical inhibition

Question 18

Who is likely to exhibit suppression?

Answer 18

1. Strab (to avoid diplopia)
2. Aniso (to avoid confusion)
3. Large heterophoria + poor vergence compensation

Question 19

For Strabismus… generally, the larger the deviation the ___ the suppression zone

Answer 19

Larger

Question 20

T/F: suppression can alternate from eye to eye

Answer 20

TRUE

Question 21

Unilateral strabismus: suppression is confined to the ___ eye

Answer 21

DEVIATING

Question 22

Frequency: the more frequent the strabismus, the ___ likely that deep suppression will be found

Answer 22

MORE

Question 23

In NON-comitant strabismus, suppression is ___ (deep/shallow)

Answer 23

Shallow (bc they experience diplopia instead)

Question 24

Aim of Anti-suppression therapy

Answer 24

Bring image formed on suppressed retina back into consciousness

Question 25

In order for the feedback mechanism of Anti-Supp therapy to work, pt must be

Answer 25

AWARE of suppression

Question 26

If suppression is deep, use ___ training environment + give examples

Answer 26

Unnatural Amblyoscope, red-green TV

Question 27

If suppression is shallow, use ___ training environment

Answer 27

Natural Vectograms, Brock string, pole mirror

Question 28

How to make sure anti-suppression therapy isn’t too easy/difficult?

Answer 28

Should not suppress 70-80% of the time

Question 29

Ways to stimulate perception

Answer 29

1. Flash 2. Blink 3. Target movement 4. Pointing 5. Touching

Question 30

Anti-Suppression Variables (9)

Answer 30

1. Attention to target 2. Brightness of target 3. Contrast of target 4. Color of target 5. Size of target 6. Flashing of target 7. Movement of target 8. Tactile & kinesthetic effects in suppression 9. Auditory effects

Question 31

What can be used to extend training range?

Answer 31

Prism & lenses

Question 32

Next step if suppression is broken and unresolvable diplopia occurs

Answer 32

D/C therapy

Question 33

Worth 4 Dot test distances

Answer 33

40 cm 1 meter 3 meter

Question 34

MFBF

Answer 34

Monocular fixation, binocular field: Transitions from states of mono to binocular processing Typically for amblyopia pts but can also jcan be used for sup

Question 35

In MFBF with TV trainer, place ___ lens over ___ eye

Answer 35

Red; suppressing

Question 36

Make MFBF more difficult

Answer 36

Smaller target