orthoptic instument

1. Manjusha lakshmi
MSc.optometry

2. Synaptophore(amblyoscope)
 It is an basic orthoptic instrument used for diagnostic
as well as therapeutic purpose.
 The word synaptophore derived from greek word.
Synaptophore
Sin with
Ops eye
Phore bearing

3. History
 The oldest model is developed by Claud worth .
 Mc. Maddox first develop slides used in early device.

4. Principle
 Haploscopic principle
it is based on the principle of division of physical
space in to two separate area of visual space each of
which is visible to one eye only.

5. Parts
 Two tubes for viewing picture
 Lenses with in the eyes piece are +6.5 DS
 Pairs of slides
 Controls allow vertical separation of the target as well
cyclotorsional adjustment
 Mirror in each tube to reflect the image of target through
the eye piece into corresponding eye.
 Scales to measure the amount of deviation
 Illumination system to increase or decrease the stimulus
luminance

7. Slides
 Simultaneous perception slides
 Foveal
 Macular
 Para macular
 Peripheral
 Fusion slides
 Steropsis slides
 Special purpose slides
 After image slides
 Haidinger brushes
 Slide with number or letters

8. Simultanous perception

9. Fusion

10. Steriopsis slides

11. Special purpose slides
After image slide
Haidenger brushes

12. Uses of synaptophore
 The uses of synaptophore divided into two
 Diagnostic uses
 Therapeutic uses

13. Diagnostic uses
 Estimation of grade of binocular single vision
 Measurement of objective and subjective angle of deviation
 Measurement of deviation in all cardinal direction of gaze
 Measurement of inter pupillary distance
 To investigate the state of retinal correspondence
 Measurement of primary and secondary deviation
 To estimate presence and type of suppression
 Measurement of fusional vergance
 measurement of angle kappa
 Measurement of AC/A ratio

14. Therapeutic uses
 It is used in treatment off
 Supression
 ARC
 Amblyopia with Eccentric fixation
 Accomodative esotropia
 Heterophorias and intermittant heterophorias

15. Preliminary setting
1. The patient’s chair and the table should be
adjusted so that he is able to look through the
centre of the eye-pieces comfortably with his
head erect.
2. The chin and forehead rest should be adjusted to
suit the patient.
3. The patient’s interpupillary distance (I.P.D.)
must be measured and the instrument adjusted
so that the distance between eye-pieces is equal
to the interpupillary distance.

17. Estimation of grade of binocular single vision
Simultanous perception
 First grade of bsv
 Tested using two dissimilar picture such as an object and a
surround E.g.: cage and lion
 Patient is asked to put the lion in cage by moving the arm
of synaptophore
 Ideally the foveal picture must be used. But the target size
should be appropriate to the patient visual acuity
Slide size Angle subtended
Foveal 1 degree
Macular 1 to 3 degree
Para macular 3 to 5 degree
Peripheral > 5 degree

18. Recording
If the patient is able to see both the pictures at a time then
S.M.P. is present and recorded as S.M.P. at zero degree or at
a particular angle.

19. Fusion
Tested using similar but incomplete picture eg: two
rabbit one lacking tail and one lacking bunch of
flowers. If fusion is present one rabbit complete with
tail and flower will be seen.
 Sensory fusion:
One tube is locked and patient is asked to create a
composite image and the position of sensory fusion was
achieved is read off the scale.
 Motor fusion:
Lock the Colum at their real corrected angle then to
measure negative fusion adduction knob adjusted and
for positive fusion abduction knob is adjusted. Then
note the value when the image split into two.

20. Recording
 Sensory fusion:
present …………degree
 Motor fusion:
Adduction BP:
RP:
Abduction BP:
RP:

21. Stereopsis
 Tested using two pictures of same object which have
been taken from slightly different angle
 if the images are fused and is seen three diamensioly
stereopsis present

22. Measurement of IPD
The patient should be seated at the
Synoptophore
inter-pupillary distance (IPD) should be
adjusted so the lines on the eyepiece
line-up with the corneal reflections

23.  Measurement of objective angle of deviation
Patient seated in front of synaptophore and IPD should be adjusted.
Smaller picture should be placed in front of RE and larger picture
placed in front of LE. An alternate cover test is performed by
alternatively switching off the light illuminating the slides.
Then according to the directions of eye movement the tube before
the non fixing eye is adjust until no movement is seen. Then the
measurement is recorded from scale. If the eyes moves out to take
fixation left arm moved in and vise versa
This can be repeated for vertical deviations.

24.  Measurement of subjective angle of deviation’
Patient seated in front of synaptophore and IPD should be adjusted
Smaller picture should be placed in front of RE and larger picture
placed in front of LE
Ask the patient to pull or push the handle controlling the non fixing
eye’s tube until the two images are super imposed.
In the presence of suppression patient fail to superimpose two
images. In this case a larger target should be introduce. If the patient
fail to superimpose in peripheral slide the patient has no BSV

25. Measurement of The Angle of Deviation For Near by The
Synoptophore:
Minus 3.00D spheres can be inserted in the lens holders
situated in front of the eyepiece lenses. The patient has to
exert 3.00D of accommodation in order to get a clear image of
the slides
In doing so , each eye exerts 3Δ of convergence for each
dioptre of accommodation-in other words, 9Δ of convergence
in one eye or 18Δ of convergence
recording the angle of deviation, we must keep this in mind and
either subtract 18Δ from or add 18Δ to the major amblyoscope
readings)
Eg:20 prisam bsae out the devation will be 20-18 = 2 prisam base out
20 prisam base in the deveation will be 20+18=38 base in

26. Recording
 SMP using macular slide
 Angle of deviation for distance
 Fixing RE
 Objective deviation: 0 degree
 Subjective deviation: 0 degree
 Angle of deviation for near
 Fixing RE
 Objective deviation: 0 degree
 Subjective deviation: 0 degree

27.  Measurement of cyclodeviation with Maddox slide
Maddox slides (white binding) can aid the assessment of 9 positions
of gaze. Horizontal and vertical deviations are assessed in the
normal way.
However, with the cross before the fixing eye the examiner may
rotate the torsion control until the patient is satisfied that it
superimposes in the centre of the green surround and all lines
should run parallel.

28.  Measurement of cyclodeviation with sp slides
Use SP slides and put lion in front of RE and cage in front of LE
The patient is asked to look at each one in turn and asked whether
cage appear level.
If the cage left hand side lower than right hand side
incyclophoria or tropia
If the cage right hand side lower than left hand side
excyclophoria or tropia
Incyclophoria corrected by rotating tortional screws towards the
patient
excyclophoria corrected by rotating tortional screws away from the
patient

29.  Retinal correspondence using SP slides
Measure objective and subjective angle using synaptophore
Find out angle of anomaly
Objective angle – subjective angle= angle of anomaly
Objective angle =
subjective angle
Normal retinal
correspondence
Angle of anomaly =
objective angle(subjective
angle zero)
Harmonious ARC
Subjective angle<
objective angle
Unharmonious ARC

30. Recording
 Fixing RE
 Objective angle: 0 degree
 Subjective angle: 0 degree
 Angle of anomaly: zero
Retinal correspondence: normal

31.  Measuring AC/A ratio
Gradient method is often used
Measure the deviation with accommodation and without
accomodation divided by change in accomodation gives AC/A ratio
AC/A =∆L - ∆O /D where ∆L – deviation with addl.lens ,∆O – original
deviation D – dioptric power of lens
Eg; :- ∆L - 6 ∆ eso ∆ o - 2 ∆ exo D – 2 D concave sphere
AC/A =6-(-2)/2
8/2 = 4 ∆/D

32.  Determination of angle kappa
A special slide consist of row of number or letters used for this
Ask the patient to look at zero. If the corneal reflex is on nasal side
the angle is positive
And if the reflex is on temporal side the angle is negative
The patient is asked to turn the letter or number until the reflex is
centered. The deviation correspond to letter or number is recorded.

33. To estimate type and presence of suppression
 The area of suppression initially mapped out by
recording the angle at which the image is suppressed.
 By lowering the angle the illumination of fixating eye
until the SMP is achieved give a rough estimation of
type of suppression.

34. Position of gaze
 In complex ocular motility cases,
all 9 cardinal positions of gaze
can be subjectively measured
along with unilateral ductions
with repeatable, standardised
conditions.
 The subjective measurement can
be performed fixing either eye in
the primary position, when the
central lock is released on lateral
versions and using the elevation
and depression controls up to
+/- 30° vertically.

35.  After image test
There are two slides available one with vertical slit and other with
horizontal slit
Then right fovea is stimulated by vertical sit for 20 sec then left fovea
is stimulated by horizontal slit for 20 sec
Ask the patient to draw position of after image

37. Haidinger’s Brushes
 Haidinger brushes correspond to macula.
 It is used for :
 To determine whether amblyopic patient fixate with
fovea or not.
 Traing technique in amblyopia to improve fixation

40. Anti suppression exercises
• chasing
•flashing
•Macular massage
•Crossing technique

41. Flashing:
This can be done with an automatic flashing
device or by manual control of the switches. The
tubes are set at the objective angle of deviation.
First one light and then the other is extinguished
at interval of a few seconds. This induces
alteration. The speed of alteration should be slow
at first but gradually increased.

42.  CHASING TECHNIQUE
 It is a subjective exercise using the smallest SMP slide
that the pt.can superimpose
 The two arms of the synaptophore are loosened and the
pt.is asked to hold the tube in front of the suppressed
eye
 Examiner moves the other tube in front the fixating eye
in a random position
 Pt. is asked to chase it and superimpose the two pictures
by moving the other tube
 As the pt.’s performance improves , smaller pictures are
used

43.  MACULAR MASSAGE
 This exercise stimulates retina of deviated eye
 It is done by moving the visual target across the
suppression scotoma
 CROSSING TECHNIQUE
 Target is moved in front of suppressed eye from
periphery of field towards suppression scotoma
 Target will disappear in suppression area & reappear on
the other side of scotoma
 The movement is continued until this area has
decreased to such an extent that pt can perceive both
target & can superimpose the two object

44. Fusion exercises
 Fusion exercises were given on major amblyoscope
with the fusion slides. Fusion range could be
increased by gradually converging both the tubes
of major amblyoscope till the fusion breaks.
Exercises were given daily or on alternate days for
10 to 15 minutes depending on the tolerance and
convenience of the patients.

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

46. Disadvantages
 Poor fixation
 Not useful in non cooprative child
 Only corneal reflex is noted
 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 expert orthoptist to handle the instrument
accurately.