Synaptophore in ophthalmology

1. SYNAPTOPHORE

2. SYNAPTOPHORE
• also known as major amblyoscope.
• it is a haploscopic device based on the mechanical
dissociation of the two eyes, by the means of two
optical tubes.
• it measures the angles of deviation
• it treats binocular vision anomalies by conventional
orthoptic method .
• it involves the use of after images,automatic
flashing and haidinger’s brushes.

3. HISTORY
• 19th century by E. Hering.
• 20th century C. Worth used this instrument for
compensation of horizontal and vertical deviation
by strabismus.
• M. Maddox defined usage of this instrument in
1931. She set 3 levels of SBV and their training.
• In Britain known as synoptophore, but in USA as
troposkop.

8. OPTICS
• 2 tubes with a right angled bend on a base with
chin and head rest.
Each tube has :
• a light source for illumination of slides
• a slide carrier at the outer end
• a reflecting mirror at right angled bend
• eye piece of + 6.5D at inner end to relax
accommodation.
• These tubes can be converged,diverged,moved
vertically together /seperately by knobs.
• tubes can be adjusted according to IPD of p/t.

10. • slide carriers can be adjusted for torsion by rotation.
• these adjustments made for horizontal ,vertical,
torsional positions on each tube can b read by
means of scales in degrees/prism diopters.
scales
• 0 degree inwards  BO prism / convergence.
• 0 degree outwards BI prism/ divergence.
light switches
• simultaneous/alternate illumination of tubes for
performing cover test.

11. HOW TO MEASURE DEVIATION
• The horizontal angle between the optical tubes varied
by moving the handles. The angles through which the
tubes are moved are recorded in degrees on the outer
edge & in prism dioptres on the inner edge of the
scales.
• The tubes lock together by central lock,allow vergence
exercises to be given, by slow convergence / divergence
of each tube equally .The amount of vergence is
recorded on the scale in degrees.
• The slide carrier can be moved upwards or downwards
upto 10 prism dioptre by the controls & vertical
deviations & vergences are recorded on the scales. To
measure vertical deviation >10 prism dioptre, slide
carriers are moved in the opposite direction by
elevation & depression controls

12. • The elevation & depression device included in the
instrument is for measuring the angle of deviation
in different vertical directions of gaze.
• Torsional deviation is measured & corrected by the
rotating slide carrier around the optical axis of the
tube. Rotation of 20⁰ on either slide is obtainable.

14. SYNAPTOPHORE SLIDES
• different pair of slide used to perform various
diagnostic & therapeutic tests.
• Based on Grades of Binocular Vision
• Simultaneous perception slide
• Fusion slides
• Stereoscopic slide

15. SIMULTANEOUS PERCEPTION SLIDE
• 2 dissimilar slides of 2 different pictures which can
be overlapped constitute a pair of simultaneous
perception slides. Each slide is presented separately
to each eye.
• Graded by their size into 3 groups –
• SIMULTANEOUS FOVEAL PERCEPTION SLIDE (SFP) :
small sized pictures, which do not exceed the size of
fovea. foveal slide 1⁰
• SIMULTANEOUS MACULAR PERCEPTION (SMP) :
The pictures slightly larger than the SFP.macular
slide 1-3⁰.

16. • SIMULTANEOUS PARAMACULAR SLIDES (SPP):
have largest pictures & form images that extend into
paramacular areas(paramacular slide1-5⁰)

17. FUSION SLIDES:
• consists of 2 similar pictures each of which is
incomplete in one small detail.
• Grading : The fusion slides are also graded
according to size in the same way as the
simultaneous perception slide
IN THE PRESENCE OF SUPPRESSION EITHER OF THE POTS WILL BE
MISSING IN THE RESPECTIVE EYE

18. STEREOSCOPIC SLIDE
• 2 pictures of same object which are taken from
slightly different angles are imaged on disparate
retinal areas in the 2 eyes & when the entire
picture is fuses, the disparity gives rise to the
perception of stereopsis of the dissimilar positions.

20. HAIDINGER’S BRUSH DEVICES
• operated by the 2 on/off switches (29), 2 speed controls
(18) and 2 reversing switching (30) present on base unit.
Iris diaphragms fitted on to the tubes helps to restrict
the field of the vision and helps to stimulate the target
point.
• The entoptic phenomenon of Haidinger’s brushes
caused by the action of polarized light falling on the
macula.
uses
• treatment of eccentric fixation
• abnormal retinal correspondence.
• The brushes can be appreciated more easily if the blue
filters are inserted in the slots

21. BIELCHOWSKY AFTER IMAGE TEST
• special slides for the to detect abnormal retinal
correspondence.
• Right fovea is stimulated with vertical and left with
horizontal bright light.
• Pt is asked to draw the position of after images .
• A pt with NRC will draw a cross .
• An esotropic p/t with ARC will draw vertical image
to the left of horizontal image to the left of
horizontal
• An exotropic pt with ARC will draw vertical image to
the right of horizontal image .

22. USES :
• Diagnostic uses : -
1. Measurement of objective angle of deviation
2. Measurement of subjective angle of deviation:
3. Measurement of deviation in cardinal directions of
gaze
4. Measurement of IPD
5. To detect the retinal correspondence
6. Estimation of grades of binocular vision
7. Measurement of range of fusion or version
8. Measurement of angle kappa

23. • Therapeutic Uses:-
1. Suppression.
2. ARC
3. Eccentric fixation
4. accomodative eso(dissociative training).
5. To improve fusional amplitude in heterophorias
& intermittent heterotropias

24. IPD
• arms of synoptophore at 0.
• p/t looks at centre of simultaneous perception slide
picture at right hand tube with R eye.
• examiner closes his R eye and aligns the reflection
of light on the centre of p/ts pupil to the central
white line on the mirror unit of tube
• repeat with left eye.
• read IPD from mm scale.

25. Measurement of objective angle of
deviation
• Simultaneous perception slides are placed.
• patient asked to look at the pictures & the arm
controlling the picture in front of the deviating eye
is moved by examiner in opposite direction until
there is no movement of the either eye on cover
test performed by alternatively turning of the light.
• The reading on the horizontal scale & vertical scale
in front of the deviating eye is the objective angle of
deviation.
• arm of synaptophore in front of the deviating eye is
at 20 ΔD BO & has to be raised 2 ΔD , the objective
angle:20 ΔD eso & 2 ΔD HT

26. measurement of subjective angle
of deviation:
• the patient is asked about the position of the pictures used.
• If the the lion in the cage then, objective= subjective angle.
• If the patient does not see the lion in the cage , ask to move
the handle with cage in front of the non fixating eye until
he sees two pictures superimposed. This is the subjective
angle.
• By means of rapid alternate flashes, check whether or not
the eyes move when the patient is asked to fixate on each
picture in turn to make sure that an actual change in the
angle between the visual axis has not occurred by either
relaxing or increasing the accommodative effort in cases of
variable angle of deviation.

27. • Problems
1. Small children may not cooperate.
2. Suppression may prevent superimposition of
picture ,use paramacular perception slides.
3. The patient may never succeed in putting the lion
in the cage & it may suddenly be seen on the opposite
side of the cage. In such cases the crossing point is
considered to be the subjective angle.

28. To detect the retinal correspondence
• If the OA=SA then ,NRC .
• When the patient reports that the targets are
separated with the instrument set at objective
angleARC.
• OA-SA= angle of anomaly.
• harmonious if OA-SA=OA. In
• unharmonious ARC, AA<OA.
• Problems
• suppression and changes in the mode of
localizations.

29. measurement of deviation in cardinal
directions of gaze
• The tube is placed before the fixing eye in the
required position of measurement & the patient
adjusts the tube before the non fixing eye until he
sees the lion in the cage. The angle of deviation is
measured in all positions of gaze.

30. measurement of primary &
secondary deviation
• SMP slides are placed.
• the patient is asked to fixate with the other eye &
the tubes are kept at zero reading. Then the light
before the fixing eye is switched off & the deviation
of the other non fixing eye is noted. The tube
before the non fixing eye is moved in opposite
direction of fixation movement until no movement
is noted.

31. to detect the presence & type of
suppression
• SFP slides are used initially . in foveal suppression:
SMP slides, in macular suppression:SPP slides are
used.
• if suppression patient sees either lion or cage.
• Suppression scotoma can be mapped out at least in
the horizontal meridian . One arm of the instrument
is rotated & the points are noted at which the target
carried by moving arm disappears & reappears.

32. measurement of range of fusion/version
• Horizontal:
• Fusion slides in place.
• the tubes are locked at the angle at which the
patient joins the pictures.
• The small screw for the adjustment of the locked
angle is used to converge or diverge the tubes.
• 4 divergence:
• fusion is estimated by moving the tubes away till
the fusion breaks(break point) ,slowly turned back
till the fusion is regained(recovery point).

33. • 4 convergence :
• ask p/t to move tubes towards each other to the point
at which fusion breaks & he sees 2 pics(break point).
• The arms are then moved back into a less convergent
position until fusion is regained(recovery point).
• Amplitudes for near :
• measured using –3.00 DSph lens placed b4 each eye.
• Vertical :
• Fusion slides are placed
• tubes are locked at angle at which the p/t joins picture.
• move 1 pic upwards or downwards & the ability of the
patient to maintain a fused picture is found out.
• The vertical fusion = synaptophore reading.
• Torsional fusional range: can also be assessed

34. findings to b recorded as:
• DISTANCE:
• 30 Δ ET ,obj & sub.
• 1st & 2nd grade of fusion at angle
• convergence to 42 Δ BO/recovery at 32Δ BO
• Divergence to 12 ΔBO /recovery at 20Δ BO
• NEAR (with -3 DSph)
• 44Δ ET ,obj & sub.
• 1st & 2nd grade of fusion at angle
• convergence to 56 Δ BO/recovery at 44Δ BO
• No divergence past angle,suppression OD

35. Measurement of angle alpha
• visual axis cross the cornea on the nasal side of
optic axis or the midpupillary line.The small angle
between optic axis & visual axis is angle alpha.
• rarely exceeds 5⁰ to 7⁰.
• + : VA cuts the cornea on the nasal side of OA.
• - : VA cuts the cornea on temporal side of OA.
• to measure :
• a special slide with of a row of numbers & letters (4
3 2 1 0 A B C D) & animal pictures for children &
illiterate placed at 1⁰ intervals kept b4 eye under
observation.

36. • The patient is asked to focus on the 0, while the
examiner looks for corneal reflex.
• The patient is asked to look either 1 letter/no: until
the corneal reflex is centered.
• The degree of deviation corresponding to the letter
or number is recorded.
• if R eye is tested & reflex is central when the patient
looks at number 2 the patient has 2⁰ -ve angle alpha
in the right eye.

37. THERAPEUTIC USES:-
1. SUPPRESSION:
• crossing technique:
• para macular SMP slides in synaptophore.
• fix the target viewed by the dominant eye & move the target
of the suppressed eye from periphery of field towards the
suppression scotoma.
• disappear in suppressed area & reappears after the entire
scotoma has been crossed.continue this back and forth
movement of the target across the suppression area until this
area until patient can simultaneously perceive both the
targets & superimpose 2 images.
• macular massage
• chasing technique
2. TO IMPROVE THE FUSIONAL AMPLITUDE IN
HETEROPHORIAS & INTERMITTENT HETEROTROPIAS

38. CONCLUSION
• It is ideal for the assessment and treatment of
ocular motility disorders by reliably performing the
most comprehensive binocular vision assessment
available today.