Testing binocular status

Question 1

What is binocular vision graded from and to in the pathway to stereopsis?

Answer 1

from point of simulataneous perception –> to fusion –> finally stereopsis

Question 2

What are 2 ways of testing simultaneous perception and fusion?

Answer 2

1. Worth’s lights (Worth 4 dot test)
2. Bagolini glasses tests

Question 3

What do Worth’s lights and Bagolini glasses tests involve?

Answer 3

dissimilar images presented to each eye and patient asked to report what they see

Question 4

What do Worth’s lights look like?

Answer 4

Question 5

What are Bagolini glasses?

Answer 5

Question 6

What can be used to assess range of motor fusion?

Answer 6

prisms - pt instructed to maintain single image with the introduction of increasing prism power

Question 7

What is considered normal stereoacuity and what may it be up to?

Answer 7

normal disparity perceived is 60s of arc, but may be up to 15s

Question 8

What is the synoptophore?

Answer 8

instrument which allows simultaneous presentation fo separate images to each eye; depending on images presented and degree of binocular vision, patient might report: simultaneous perception of two images, fusion of two images, or perception of depth in a fused image

Question 9

What are 3 outcomes that a patient may report when binocular status is tested with the synoptophore?

Answer 9

1. simultaneous perception of two images
2. fusion of two images
3. perception of depth in a fused image

Question 10

What are 5 tests of binocular status?

Answer 10

1. Titmus
2. TNO
3. Lang
4. Frisby
5. Synoptophore

Question 11

What is the icon used for each of the 5 tests of binocular status?

Answer 11

Question 12

What is the mechanism used for each of the 5 tests of binocular status?

Answer 12

1. Titmus: polarised glasses
2. TNO: red-green glasses
3. Lang: intrinsic cylinder lenses
4. Frisby: intrinsic plate thickness
5. Synoptophore: separate eyepieces

Question 13

Are there monocular clues for each of the 5 tests of binocular status?

Answer 13

1. Titmus: no
2. TNO: no
3. Lang: yes if not held perpendicular
4. Frisby: yes if not held perpendicular
5. Synoptophore: no

Question 14

What is the disparity that each of the 5 tests of binocular status ranges between?

Answer 14

1. Titmus: 40-3000s of arc
2. TNO: 15-480s of arc
3. Lang: 550-1200s of arc
4. Frisby: 15-600s of arc
5. Synoptophore 90-720s of arc