Assessing Correspondence

Question 1

What is the perception of two of the SAME object projected in Different visual directions?

Answer 1

Diplopia

Question 2

What is the perception of two different objects projected in the SAME visual direction?

Answer 2

Confusion

Question 3

Suppression

Answer 3

perceptual solution for diplopia/ confusion

Question 4

What is the cortical reprogramming of the visual directions of various points of the retina?

Answer 4

anomalous correspondence

aka: ARC

Question 5

What is it called when the foveas of the eyes are cortically linked so that images projected on the foveas are cortically combined to form a single percept in a common visual direction?

Answer 5

Normal Correspondence

Question 6

How is AC different than EF?

Answer 6

AC: binocular; exists to fix a problem (diplopia or confusion); harmonious: able to fuse
EF: monocular; IS the problem; only comes into play when the eye is fixating (d/t suppression)

can happen at the same time

Question 7

What is point Z?

Answer 7

Location of the image of the object of regard in turned eye

where the image we are looking at falls on the retina

NOT a fixed location

Question 8

What is point a?

Answer 8

location in turned eye associated with fovea of fellow eye

fixed location; “anomalous point”; can be moved with VT

cortically linked to the other eye; can be at point z or any other point

Question 9

objective angle (<D)

Answer 9

angle from where the image of the object is located on the retina (Z) to the fovea

from Z to F as the eye rotates

assessed with PACT, MA

Question 10

Subjective Angle

Answer 10

Angle from Z to the point in the eye that corresponds to the fovea of the other eye (a)

assessed with MR, red lens, HL, etc

Question 11

What is the angle of anomaly (<A)

Answer 11

Angle from the fovea to the anomalous point

assessed with HBAIT

find <D and <S; angle of anomaly is whatever is left; usually calculated; if the same, no AC

Question 12

Harmonious Anomalous correspondace

Answer 12

When the objective angle equals the angle of anomaly

Question 13

Which two points are in the same place in harmonious Anomalous Correspondence?

Answer 13

Z and the anomalous point

Question 14

In HAC, why doesn’t the patient report diplopia?

Answer 14

The subjective angle is always zero

the anomalous point is where the image is

Question 15

What does the patient perceive in Unharmonious anomalous correspondence?

Answer 15

A smaller deviation than what is actually there

Question 16

Where is the anomalous point in UAC?

Answer 16

closer to the fovea than in HAC

Question 17

When does Paradoxical Anomalous Correspondence occur?

Answer 17

Typically post surgery

Question 18

Where is the anomalous point in PAC II?

Answer 18

on the opposite side of the retina than expected

patient will perceive a larger deviation than what is actually there

Question 19

Where does the patient perceive the deviation in PAC I?

Answer 19

deviation in the opposite direction than what is actually there

Example: an esotrope will report crossed instead of uncrossed diplopia

Question 20

What are the 3 theories of AC development?

Answer 20

1. Innate
2. Motor
3. Sensory

Question 21

What is implied in the innate theory?

Answer 21

AC is the cause of strabismus rather than the result

contradictory evidence exists

Question 22

What type of eye movements under the motor theory produce changes in both eye movements AND correspondence?

Answer 22

registered eye movements

impulse from brain changes location of the eye and indicates which correspondence to use (perceptual processesing area of brain responsible for visual direction)

Question 22

Which theory states that strabismus and AC are separate anomalies with a common neurological source?

Answer 22

Motor theory

whatever cuased the eye turn, also changed the directional sense

Question 23

According to the motor theory….

Which type of eye movement is accommodative vergence?

Answer 23

Non-registered Eye Movement

impulses from brain communicate only with EOMS; produce only eye mvmt

Question 24

What is shifted to match the motor deviation under the sensory theory of AC development?

Answer 24

primary visual diretion

helps restor some semblence of binocularity

Question 25

What happens to AC over time according to the sensory theory of AC development?

Answer 25

AC deepens over time

Bc AC is sensory adaptation to abnormal motor conditions it requires time to become embedded

Question 26

Which type of AC does sensory theory explain?

Answer 26

Harmonious AC

there are problems with UAC

Question 27

Why might different tests for AC provide different results?

Answer 27

1. embeddedness
2. measurement error
3. unsteady EF
4. Variation in deviation magnitude between tests

Question 28

Eccentric fixation in the same direction does what to the full amount of the angle of anomaly?

Answer 28

it hides it

nasal EF w ET, EF will mask angle, measured will be smaller than true

also hides full amount of objective angle

Question 29

Which type of strabismus is the Haidinger’s brush and afterimage test ideal for?

Answer 29

small angle strabismus

Question 30

What is measured by HBAIT?

Answer 30

angle of anomaly with concurrent assessment of EF

Question 31

What tags the fovea of the deviated eye in HBAIT?

Answer 31

the brush

Question 32

if the brush and the afterimage are in the same place, what type of correspondence does the patient have?

Answer 32

Normal

Question 33

How is Worth 4-dot used to assess correspondence?

Answer 33

comparing subjective and objective angles

Question 34

UCT/ douse is used to determine what?

Answer 34

anomalous correspondence

Question 35

For worth 4 dot for correspondence, which type of prism is used?

Answer 35

corrective

uncrossed = base out; crossed = base in