2. Definition
It is when more than one image ( two ) of the object of
regard are seen simultaneously
It is Greek work which means double vision. It is caused
due to the breakdown in the fusional capacity of the
binocular system.
3. Mechanisms
◦ More than one image of the object of regard is formed in
the retinae of one or both eyes ( monocular diplopia)
◦ The eyes lose their simultaneous alignment with the object
of regard (incomitance of ocular alignment – binocular
diplopia)
◦ The eyes although aligned, send images to the brain which
disallow fusion ( aniseikonia )
◦ Rarely, purely cerebral mechanisms
4. Is the double vision present even on monocular
eye closure?
6. Binocular Diplopia
Occurs when both the eyes work together and resolved by occlusion of
either eye.
1. Physiological
2. Concomitant- decompensating heterophoria(angle of deviation is same in
different directions of gaze)
3. Inconcomitant
(i) Myogenic - thyroid ophthalmopathy
(ii) Neuromuscular junction disorders - myasthenia,
(iii) Paralytic - Nuclear/Infranuclear
- Supranuclear lesions are not normally associated with diplopia
(iv) Restrictive -blow out fractures, orbital tumours,Browns syndrome
7. Is there a mis alignment?
If so, in which directions ( or distances ) of gaze?
Which are the hypofunctioning ( and
hyperfunctioning ) muscles?
Do they have a neurogenic pattern, or a restrictive
pattern or a neuromuscular pattern or a myogenic
pattern?
9. Leading questions
Is the diplopia more for distance or near?
Is the diplopia predominantly horizontal or vertical?
In which direction of gaze are the images maximally
separated?
To which eye does the “outer” image belong?
Is there a predominant tilt?
In which position of gaze does the tilt increase
maximally?
10. Diplopia is maximum ( separation of images) in the
field of action of the paralysed muscle.
The false image ( the image belonging to the eye
with the hypofunctioning muscle ) is always
peripherally situated
11. Diplopia chart
is the record of subjective separation of double
images in the nine positions of gaze.
Two methods
1. Simple method
2. Electronic devices(hess n lees screens )
12. The method
Comfortable with his head erect and should preferably be still
throughout the examination.
carried out in a dark room.
A red glass is put in front of one of the eyes (red in front of
right, R for R, is a convention). It is desirable to use Armstrong
goggles since these are shaped to fit the orbital margin
examiner holds the torch (vertical source of light) at around ½
m or 1 m (It is important to mention the distance on the chart).
This source of light could be horizontal if the complain is of
vertical separation of images
The light is held directly in front of the patient at first.
13. If the patient notes a double image, the relative position
of these images is noted. The light is now carried to the
right and then to the other 8 positions of gaze.
If there is no double vision in primary position, the
position in which double vision appears and is maximal is
to be noted.
In each gaze position the patient must be asked whether
the images are,
parallel , distance between two images & tilt if
present;
colored pencils can be given to patient to show the
separation.
14.
15.
16.
17. Interpretation
i. If two images are joined together—
no diplopia
ii. If images are separated—confirms
diplopia.
iii. Maximum separation is in the
quadrant in which (the muscle moves
the eye) the muscle is restricted.
iv. The image is displaced towards the
field of action of the paralyzed muscle.
18. v. If horizontal separation with
uncrossed images—esodeviation.
vi. If horizontal separation with
crossed images—exodeviation.
vii. If vertical separation with
uncrossed images—oblique muscles
involved.
viii. If vertical separation with crossed
image—vertical recti muscle involved
19. Hess chart
Based on the principle of confusion
The principle is foveal projection. Based on the
Hering’s and Sherrington’s law of innervation.
The dissociation of two eyes is by the means of colors
or mirrors (as in Lees” screen).
Allows for identifying the position of one eye, while
the other eye fixes in different positions of gaze.
Allows for more objective follow up also.
20. The test is performed with each eye fixating in turn.
It is done at 50 cms.
Patient wears complimentary red and green glasses.
The red glasses are placed on the right eye first (Red for right, R
for R)
The chart has electronically operated board with small red lights.
The red lights can be illuminated as needed separately.
Patient is asked to place the green light in each of the points on the
red light as illuminated on the chart.
Next the goggles are changed and the left eye has red goggles and
the eye to be tested is right eye.
21.
22. Example 1
Bilateral Superior oblique palsy
Both the charts are to be seen carefully. It is obvious that both the
charts show superior oblique underaction. There is a contra lateral
inferior rectus overaction. Both the fields are extorted. The midline
is shifted in both eyes indicating diplopia in primary position
(torsional). Right eye shows slightly greater underaction of superior
oblique.
Both the charts appear extorted. This was a patient of traumatic
bilateral superior oblique palsy.
23. Example 2
Both the eyes show small fields. Overaction is seen in both
the eyes on the nasal side. Inner field is closer to outer one
so likely to be fresh palsy then an old/ recovered one.
Midline is shifted nasally therefore the eyes are also shifted
nasally. The patient had a bilateral lateral rectus palsy of
recent onset. .
24. Example 3
Right eye field in this example is smaller and the left eye field is larger.
The outer upper line is closer to the inner line; the lower one is at a
distance. The superior function is lost, that is the inferior oblique and
the superior rectus is underacting. The central point is moved
downwards so diplopia is there in primary position
This was a patient of the entrapment of the inferior rectus.
Example 4
The field of right eye is smaller compared to the left eye. There is an
obvious underaction of inferior oblique. Superior rectus of left eye
shows overaction. This was a patient of Right eye inferior oblique
palsy. It is important to distinguish this from a Brown’s syndrome
which may be acquired and may show a similar picture.
25. Treatment
1. conservative (glases/prisms)
2. surgical(squint correction )
Primary aim is to prevent diplopia
Occlussion of one eye with
patch/opaque contact lens
If deviation is less prisms can be given
In neurological cause we can wait for
6 months to one year
26. If there is no improvement even after
one year in paralytic conditions patient
can be advised for surgical correction
for deviation to prevent diplopia
Principle is--- correction should be in
such a way that pt should not have
any diplopia in primary and downward
gaze of position….