Tests for stereopsis, tests for fusion, tests for diplopia, tests for suppression, tests for retinal correspondence, Bagolinis straited test, worths four dots test, synoptophore, simultaneous perception slides, fusion slides, stereopsis slides, titmus test, TNO test, Frisby test, Random dot E test, langs two pencil test, after image test, visouscopy test, red filter test, sbiza bar, 4 prism diopter test, amsler grid, langs stereo test, crossed diplopia, uncrossed diplopia, suppression scotoma vertical diplopia, anomalous retinal corrospondence, enlarged panums fusional area, fixation ophthalmoscope, visual maturation, binocular single vision, stereoacuity, orthoptic instruments,

1. Tests for Binocular Vision
all the tests are aimed at assessing the presence or absence of:
✓Normal or abnormal retinal correspondence
✓Suppression
✓Simultaneous perception
✓Fusion
✓Stereopsis
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2. before any test is undertaken it is essential to assess the:
• visual acuity
• fixation in the squinting eye
• direction and size of deviation
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3. Tests for Retinal Correspondence
clinically the tests used can be based on either of the two principles:
1. assessment of relationship between the fovea of the fixing eye and the
retinal area stimulated in the squinting eye; this includes:
• Bagolini's striated glasses test
• Red filter test
• Synaptophore using SMP slides
• Worth's 4 dot test
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4. 2. assessment of the visual directions of the two foveas; included in this
are:
• After image test (Hering Bielschowsky)
• Cuppers binocular visuoscopy test (foveo-foveal test of Cuppers)
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5. Bagolini's Striated Glasses Test
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6. • required equipments are: BSG’s, torch
• BSG’s are glasses of no dioptric power that have many narrow
striations running parallel in one meridian
• these glasses cause the fixation light to appear as an elongated streak
perpendicular to the striations
• the lenses are usually placed at 45 degree OS and 135 degree OD and
the patient fixates for distance or near
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7. • this test is used to determine the direction of a pseudofovea, abnormal
retinal correspondence, suppression and diplopia
• the test is performed under dim light
• if the patient uses prescription glasses ask him to wear it
• place the BSG infront of the patient’s eye
• shine a light towards the patients nose bridge
• the patient is asked to describe or draw what they have seen
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8. Ask the following questions:
• how many lights do you see?
• how many lines do you see?
• do the lines cross?
• are the two lines seen at the same time?
• do the lines intersect through the light?
• do the lines have any gaps in them?
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10. Synoptophore (Major Amblyoscope)
• derived from greek word: syn-with, ops-eye and phoros-bearing
• is haploscopic device based on the mechanical dissociation of the two
eyes by means of two optical tubes
• used for both diagnostic and therapeutic purposes
• used to diagnose anomalies of BV with targets that are presented to
each eye
• can be used to detect and quantify suppression, determine retinal
correspondence, measure the size and shape of a suppression scotoma,
measure primary/secondary deviations and determine fusional
potential
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12. Synoptophore slides
• Simultaneous perception slides (foveal, macular, paramacular and
peripheral)- red
• Fusion slides- green
• Stereopsis slides-yellow
• Special purpose slides-blue
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14. Diagnostic uses
• estimation of grade of BSV
• measurement of subjective and objective angle of deviation
• to investigate the state of retinal correspondence
• to estimate the presence and type of suppression
• measurement of fusional vergence
• measurement of angle kappa
• measurement of AC/A ratio
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15. Therapeutic uses: it is used in the treatment of
• Suppression
• ARC
• Amblyopia with eccentric fixation
• Accomodative esotropia
• Heterophorias and intermittent heterophorias
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16. Worth's 4 dot test
• used for assessing a patient’s degree of binocular vision or the status of
peripheral binocular cooperation
• contain four dots (1 red, 2 green and 1 white)
• can be done at distance (6m) or near (33cm)
• the required equipments are: illuminated box or flash light containing
the four dots and red green filter
• if the patient uses prescription glasses ask him to wear it
• the test is performed under dim light
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17. • put the red filter over the right eye and the green filter over the left eye
• turn on the flash light slightly below the line of sight
• cover the LE and ask how many dots they see (they should report 2
red)
• cover the RE and ask how many dots they see (they should report 3
green)
• for binocular test with both eyes uncovered ask how many dots they
see (if normal fusion is present they should report 4 dots)
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18. Patient’s response and their interpretation:
1. if 4 dots seen (one red dot in the top, two green dots either side and
one orange dot at the bottom): BSV
2. only 3 green dots: patient is seeing through the left eye: Right
suppression
3. only 2 red dots means left eye image is suppressed: Left suppression
4. 3 green dots and 2 red dots alternatively: right eye image and left
eye image is suppressed alternatively: Alternate suppression
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19. 5. 5 dots i.e 2 red dots on the right and 3 green dots in the left side
which means RE image is on the right side and LE image is on the left
side: Uncrossed diplopia
6. 5 dots i.e 3 green dots on the right and 2 red dots on the left side
which means RE image is on the left side and LE image is on the right
side: Crossed diplopia
7. 5 dots i.e 2 red dots above and 3 green dots below: Vertical diplopia
with Rt hypotropia or Lt hypertropia
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20. 8. 5 dots i.e 3 green dots above and 2 red dots below: Vertical diplopia
with Lt hypotropia or Rt hypertropia
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21. After image test (Hering Bielschowsky)
• to determine the relationship between the foveal projection of both
eyes
• performed on synoptophore using after image slides
• the fixating eye is stimulated with a horizontal line and the deviating
eye with the vertical line (for 10-15 sec each)and the patient is asked
to see at its center
• then the patient is asked to close his eyes and open the eyes after a few
sec then look at the wall
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23. Results
• in NRC the patient will see the perfect cross
• in cases of manifest strabismus because the foveae project to different
points in space a displaced after-image is produced by the deviating
eye
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24. Visuoscopy test
• visuoscope is a modified ophthalmoscope that projects a fixation target
on the fundus
• determines whether the two foveas have common or different visual
directions
• it permits quantitative analysis of the angle of anomaly when eccentric
fixation is present
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26. Tests for presence of fusion
• Worth’s 4-dot test
• Bagolini’s striated glasses
• Synaptophore
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27. Tests for Stereopsis
• Titmus test
• TNO random dot stereo test
• Lang’s stereo test
• Random dot E test
• Frisby test
• Stereoscopic targets presented haploscopically in major amblyoscope
• Lang’s two pencil test
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28. Titmus test
• measure how minutely the two
eyes can discern differences in
the distances of objects from the
observer
• three tests are presented:
1. the house fly test- establishes
the presence of gross stereopsis
2. the circle patterns-tests fine
depth discrimination.
3. three rows of animals
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29. TNO Test
• consists of 7 plates to be viewed,
with red-green goggles, that
carry figures that can be seen
only when both eyes cooperate to
give stereoscopic vision
• within each plate the dots of one
color form the target shape
• tested at a distance of 40 cm
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30. Frisby test
• consists of 3 transparent plastic
plates of varying thickness(6,3
and 1mm)
• each plate consists of 4 squares
produced by random shapes
printed on one side
• one of the squares contains a
hidden circle
• 6, 3 and 1mm plates produces
stereopsis of 340, 170 and 55 sec
arc respectively
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31. Random dot E test
• consist of demonstration plate
and two test plates
• each of the test plate is printed
with a polarized random dot
pattern and requires the use of
polarized glass
• a patient who has stereopsis will
see a raised letter E in the
random dot pattern of one of the
test plates, where the other test
plate is blank
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32. Lang two pencil test
• to detect gross stereopsis
• the patient attempts to place a
pencil on top of one held by
examiner
• patient who possess stereopsis
will find it easier to perform the
test with both eyes open than
monocularly
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33. Tests used to diagnose suppression are:
• Worth's four dot test
• Synoptophore
• Amsler Grid
• 4 Δ prism base out test
• Red filter test
• Bagolini’s striated glasses
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34. Red Filter Test
• primarily used to assess the depth of suppression and ARC
• patient fixes on torch – a single torch (red) should be seen due to either
suppression or ARC
• the red filter glass is placed infront of the fixating eye- always
commence with the lightest filter
• increase filter until diplopia is appreciated (one red and one white
light)
• the filter of last single vision is documented
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36. 4 Δ Prism base out test
• quick, sensitive screening test to assess whether bifoveal fusion or
suppression of one fovea is present
• confirms the presence of microtropia
• sudden displacement of an image with a base out prism from one
fovea onto the parafoveal temporal retina will elicit a refixation
movement if the image has been shifted within a normally functioning
retina, but no movement will occur if the image has been shifted
within a nonfunctioning (that is, scotomatous) area
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38. Amsler grid chart
• used to plot central and
paracentral scotomas
• the chart usually consists of a
square grid of black lines on a
white background
• the patient describes or draws
how the grid appears, thus
demonstrating the scotoma
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