The synoptophore is an instrument used in orthoptics to test binocular vision. It presents different images to each eye to test fusional abilities. The synoptophore was developed in the early 20th century based on the haploscopic principle. It uses mirrors and lenses to direct different images to each eye. Various models have different additional features like afterimage devices, automatic flashing, and measurement of vertical/torsional deviations. A wide range of slides can test functions like stereopsis, fusion, suppression, and retinal correspondence. The synoptophore is useful for both diagnosing binocular vision disorders and providing vergence therapy.

1. SYNOPTOPHORE
Presented by
Loknath Goswami
Arundhati Hatikakoty
Kabita Baruah
B. Optom 3rd year
Ridley College of Optometry

2. Presentation layout
• History
• Introduction
• Principle
• Models
• Parts and slides
• Uses
• Advantages and disadvantages
• Revision

3. History
In 20th century, Claud Worth designed
the Worth-Black amblyoscope which was
later modified by H. M. Black
Claud Worth

4. History
1914- Ettles made a stand amblyoscope,
the Synoptophore, to overcome the
clumsiness of the Worth instrument.

5. History
1930- Green patented his own Synoptophore ,
introducing a set of slides. It has been the basis of
numerous sets of Synoptophore slides that followed
Moorfields synoptophore
Clement Clarke’s major synoptophore

6. INTRODUCTION
• An instrument for diagnosing imbalance of
eye muscles and treating them by orthoptic
methods
• An instrument used in orthoptic to present to
the subject images at different angles of
convergence or divergence so that the
fusional ability can be tested
Syn Opto phore
Both Eye Range

7. Principle
• Haploscopic principle
• Synoptophores are designed on the principle
of division of “physical space” into two
separate areas of “visual space” each of which
is visible to one eye only.

8. Principle
• The object and its image are “conjugate”,
being join by the optical system so that if test-
object pictures are placed in a choosen
position relative to each other it follows that
the image will be directed into similar relative
positions
• By altering the position of the test objects in
an instrument that their image can be made
to stimulate selected retinal areas as required

9. Optics
• A ray of light from the picture at P strikes the mirror
at O, is reflected in the direction of OD and appears
to come from a point X, at a distance behind the
mirror equal to OP

10. Optics
• The eye piece contains a convex lens D whose
focal distance is DX = (DO + OP)
• The image of the test object slide is therefore
situated at the principle focus of the lens
• Rays of light emanating from the principle
focus will, after refraction by the lens D in the
eye-piece, emerge as parallel rays; this means
that an eye when viewing the image is relaxed
or focused for distance, no accommodation
being required

11. The Major Synoptophore Model 2051
• In addition to measuring
deviation and
management of binocular
vision function, there are
provisions for afterimages,
automatic flashing and
haidinger’s brushes
• 2051 is the most
comprehensive one with
all the above mentioned
additions

12. Synoptophore Model 2052

13. Model 2052
• This synoptophore resembles model 2051,
with the exception that the haidinger’s Brush
device is not included
• The automatic flashing unit is precisely the
same but instead of being attached to the
base of the instrument it is housed in a well in
the table
• The after-image device is the same as that in
model 2051

14. Synoptophore Model 2053

15. Model 2053
• This is the basic model synoptophore
• It has all the features of Models 2051 and
2052 except the Haidinger’s brush, after-
image and automatic flashing devices

17. Model 2051
• The base of the instrument contains the
electrical components and controls needed for
operation, including the transformer for
reducing the mains current to the required
low level
• A voltage selector enables the synoptophore
to be used on any A.C. current

18. Model 2051
• Rising from the base
are two columns each
of which supports an
optical tube

19. Model 2051
• The two optical tubes each contain
– A low intensity light source
for the illumination of slides
– A high intensity light source
for creating after-images and
Haidinger’s brushes
– A slide carrier, with a plastics
diffusing screen
– An iris diaphragm for
reducing the field of vision
when Haidinger’s brushes are
used
– A reflecting mirror and an
eyepiece lens of +6.50 D sph

20. Model 2051
• The slide carrier is situated at the focal point
of the eyepiece lens, thus parallel rays of light
emerge which should ensure relaxation of the
patient’s accommodation
• Accommodation can be induced by the
introduction of minus lenses, placed in the
lens holders which are situated in front of the
eyepiece lenses

21. Model 2051
• The optical tubes can be
adjusted by means of
controls so that the
distance between the
centres of the eye-piece
lenses and the patient’s
IPD are the same

22. Model 2051
• The horizontal angle
between the optical
tubes can be
increased or
decreased by moving
the handles which are
sloped downwards so
that even the smallest
child is able to grip
them comfortably

23. Model 2051
• The tube-lock
together with the
central lock allow
vergence exercises to
be given, so that each
eye slowly converges,
or diverges, to an
equal extent

24. Model 2051
• The angles through
which the tubes are
moved are recorded
in degrees on the
outer edge and in
prism diopters on the
inner edge of the
scales

25. Model 2051
• The slide carriers can
be moved upwards
or downwards to the
extent of 10 pd by
the controls, and
vertical deviations
and vergences are
recorded on scales.

26. Model 2051
• If it is necessary to
measure a vertical
deviation greater
than 10pd the
elevation and
depression controls
may be used to
augment the
movement

27. Model 2051
• Torsional deviation is
measured and corrected
by operating one or
other the controls, the
effect of which is to
rotate the slide carrier
around the optical axis
of the tube
• Rotation of 20 degrees
on either side of zero is
obtainable and is
recorded on the scales

28. Model 2051
• On the base of the instrument there are two
rheostats
• These enable the illumination of each slide to
be varied

29. Model 2051
• When examining patients shortly after
operation it may be desirable to reduce the
luminousity of one or both lamps on account
of photophobia; and when examining or
treating amblyopes it may be advisable to
increase the illumination in front of the
amblyopic eye and reduce it infront of the
other eye

30. Model 2051
• The two buttons are microswitches each of
which when depressed, extinguishes the lamp,
illuminating the ipsilateral slide. This device
avoids the necessity of covering one eye in
order to detect ocular movement when
measuring the angle of deviation objectively

31. Model 2051
• A rotary switch on the base operates each of
after-image lamps in turn and the slide
illumination lamps are automatically
extinguished whilst the test is carried out

32. Model 2051
• In order to maintain the after-image for a
period of time and to use them in treatment of
abnormal retinal correspondence it is necessary
to provide the patient with an alternate light
and dark background
• One or both of the tubes can be intermittently
illuminated
• If both tubes are intermittently illuminated the
period of illumination may be simultaneous or
alternating

33. Model 2051
• A variety of speeds and different lengths of
light and dark phase can be produced by
manipulating the various controls on the
flashing unit
• Thus variations can be made are:

34. Model 2051
1. Simultaneous flashing: both lamps flashing for
the same sequence of light and dark, the periods
of light and dark being variable
2. Alternate flashing: in which the period of light in
one slide carrier coincides with a period of dark in
the other, and vice versa
3. One lamp flashing according to the light and dark
setting, whilst the other lamp is extinguished
4. One lamp flashing variably according to dial
setting whilst the other remain illuminated
continuously

35. SLIDES USED IN SYNOPTOPHORE

36. SLIDES
• SIMULTANEOUS PERCEPTION SLIDES –
• These are two dissimilar slides of two
different pictures which can be overlapped
• Each slide is presented separately to each eye
• Each slide size has been calculated to subtend
a different angle at the nodal point of the eye
• These are graded into 3 groups by their size
1) Foveal
2) Macular
3) Paramacular

37. 1) Foveal-
• These slides have small sized pictures
• They do not exceed the size of the fovea
• Foveal slide- 1°
2) Macular-
• They have pictures slightly larger than the foveal slides
• Macular slide 1-3°
3) Paramacular-
• They have the largest pictures that extends into
paramacular areas
• Paramacular slide 1-5°

38. Some of the simultaneous perception
slides are:

39. Some of the simultaneous perception
slides are:

40. Some of the simultaneous perception
slides are:

41. Some of the simultaneous perception
slides are:

42. FUSION SLIDES
• Consists of two dissimilar pictures each of
which is incomplete in each details. For ex-
two rabbits each lacking a tail or a bunch of
flowers
• If there is presence of fusion in a patient then
he will see the complete image of the rabbit
holding a bunch of flowers
• In the presence of suppression either tail or
bunch of flowers will be missing

43. Some of the fusional slides are:

44. Some of the fusional slides are:

45. Some of the fusional slides are:

46. Some of the fusional slides are:

47. STEREOPSIS SLIDES
• Consisting of two pairs of same objects
hypothetically taken from slightly different
angles to indicate depth perception
• These slides are inserted into the slide holders
with the controls of each slide positioned
towards or away from the subject.
• The patient is then required to describe the
apparent effect

48. Some of the slides used for stereopsis
testing are:

49. Some of the slides used for stereopsis
testing are:

50. Some of the slides used for stereopsis
testing are:

51. Some of the slides used for stereopsis
testing are:

52. SPECIAL PURPOSE SLIDES
• These special purpose slides are used to
assess Abnormal Retinal
Correspondance(ARC).
• Using the illumination settings on
Synoptophore, horizontal and vertical
alignment can be achieved in the presence of
steady foveal fixation
• These are graded into 3 groups

53. AFTER IMAGE SLIDE
• Horizontal streak and one vertical streak, each
with central red fixation mark

54. Slides with numbers and letters

55. HAIDINGER BRUSHES
• Haidinger brushes are an entoptic
phenomenon seen only at the fovea
• It is produced by viewing a revolving polarised
light through a blue filter

56. Diagnostic Therapeutic

57. Diagnostic
• Measurement of deviation
– With each eye fixing (Paralytic squints)
– Objective angle and subjective angle (ARC)
– In different gaze position (incomitant squints)
– Horizontal, vertical and torsional deviations can be
measured
• Special functions as adaptability to function in
aniseikonia with help of special slides
• “After image” testing

58. Diagnostic
• Assessment of binocular status:
– Simultaneous macular perception
– Fusion
– Stereopsis
• For foveal, macular and paramacular retinal areas
• Measurement of range of fusion
• Cases with incomplete suppression can also be
tested by using differential illumination and by
using flashing devices
• Appreciation of entoptic phenomena, Haidinger
brushes

59. Therapeutic
• Fusional vergence exercises
• Management of suppression-antisuppression
exercises
• Treatment of anomalous retinal
correspondence
• Amblyopia therapy with the help of Haidinger
brushes

60. Advantages
Disadvantages

61. Advantages
• Accurate measurement is possible
• Tube can move separately
• Large selection of suitable slides are available
• The patient’s eye can be seen by the examiner
and the corneal reflections can be observed.
• There can be rapid interchange from objective
to subjective conditions

62. Disadvantages
• Not useful in non cooperative child
• Bulky instrument, difficult to transfer from
one place to other.
• Though the slides are kept in optical infinity
distance but still it stimulates proximal
accommodation of the patient.
• Needs skill to handle the instrument
accurately.

63. 1) Optical tube
2) Chin rest
3) Head rest
4) Handles for
adjustments of
horizontal angles
between the tubes
5) Scales for
measuring
horizontal
deviations
8) Slide carrier
11) IPD controls
Parts of Synoptophore

64. 6) Central lock
7) Horizontal vergence scale
9) Vertical controls
10) Vertical deviation scales
12) Chin rest controls
13) Torsional deviation controls
14) Elevation depression
controls
15) Elevation depression scales
16) Light and dark phase
controls
17) Rapid and variable switch
18) Speed controls
19) Lamp housing
Parts of Synoptophore

65. 20) Horizontal vergence
controls
21) Selector switch
22) Hand flashing switch
23) Dimming rheostats
24) Horizontal tube locks
25) Simultaneous/ alternating
switch
26) Torsional deviational scales
27) IPD scales
28) Mains
29) on/off switches(haidinger’s
brushes)
30) Reversing switch
Parts of Synoptophore

66. References
• Lyle and Jackson’s, Practical opthoptics in the
treatment of squint, 5th edition, page no. 96-105
• Pradeep Sharma, Strabismus simplified, page no.
211-13
• https://www.merriam-
webster.com/medical/synoptophore
• http://medical-
dictionary.thefreedictionary.com/synoptophore