2. Definition
It gives a pictorial record of diplopia in cases where
there is separation of 2 images, in the nine positions
of gaze.
It is Greek word which means double vision.
It is caused due to the breakdown in the fusional
capacity of the binocular system.
PRINCIPLE : Each retinal point has its own value
of direction in gazes.
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
- Supranuclearlesions are not normallyassociated withdiplopia
(iv) Restrictive -blow out fractures, orbital tumours,Browns syndrome
8. 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
9. DATA DERIVED FROM DIPLOPIA
CHART
i. The areas of single vision and diplopia
ii. The distance between the two images in the
areas of diplopia
iii. Whether the images are on the same level or
not
iv. Whether one image is inclined or both are erect
v. Whether the diplopia is homonymous or crossed.
10. PREREQUISITES FOR DOING
DIPLOPIA CHARTING
i. Patient should have binocular single vision.
ii. Good visual acuity.
iii. Patient should be cooperative.
11. The SIMPLE 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 useArmstrong
goggles since these are shaped to fit the orbitalmargin
examiner holds the torch (vertical source of light) at around ½
m or 1 m (It is important to mention the distance on thechart).
This source of light could be horizontal if the complaint is of
vertical separation of images
The light is held directly in front of the patient at first.
12. 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.
15. 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.
16. 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
17. DISADVANTAGES
i. It is mainly a subjective test.
ii. Needs a well cooperative patient.
iii. Test is not reproducible.
iv. In many cases the patients are uncooperative or
their intelligence is obscured by intracranial
disease or contracture of the antagonistic muscles
may have set in.
v. The test may give false interpretations if the
paresis unmasks a latent squint or the patient
starts fixing with the paralyzed eye, especially if
18. TREATMENT
1. conservative (glasses/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
19. 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