2. Definition
Diplopia or double vision is the subjective
complaint of seeing two images of an object
instead of one.
3. What does the faculty of BSV
require?
Perfect ( or near perfect ) alignment of the
visual axes simultaneously on the object of
regard
Perfect ( or near perfect ) retinal
correspondence
Perfect central ( or paracentral ) fusional
capability.
Perfect ( or near perfect ) optics to allow
only one image to be formed on the retina
and the same single image to be formed
on the other
7. Mechanism of Diplopia
The two most common mechanisms for
diplopia are visual axis misalignment and
abnormalities of the ocular media or
refractive errors .
8. Binocular diplopia
In ocular misalignment, the image of an
object that is being viewed does not fall on
fovea of both retinas.
This causes binocular diplopia which
disappears on closing one eye
10. Monocular Diplopia
The abnormalities of the ocular media or
refractive errors lead to monocular diplopia
that persists in the affected eye even if the
other eye is closed.
11. Functional Diplopia
Diplopia without any pathological cause is
termed functional.
However, it is a diagnosis of exclusion and a
thorough examination and appropriate
investigations are mandatory to rule out a
pathological cause first.
12. Importance
It is important to differentiate monocular
from binocular diplopia.
The diagnosis of monocular diplopia usually
obviates the need for a detailed neurological
examination
13. Causes of Monocular Diplopia
Refractive error
Anomalies of the tear film
Corneal defect (e.g., irregular astigmatism)
Cataract
Media opacities
Retinal defects
14. Causes of Binocular Diplopia
The causes are multifactorial but results most
commonly from an acquired misalignment of
the visual axis secondary to recent onset of
extraocular muscle paralysis.
15. History
A detailed history. Points
1. When and how did the double vision started?
2. Whether diplopia disappears or persists after
closing one eye?
3. Associated symptoms with double vision if any?
4. Is it constant in all gazes or more in a particular
gaze?
5. Is it more for far or near fixation?
16. HISTORY
6.Whether the images are horizontally, vertically
or obliquely separated?
7. Is the diplopia constant, intermittent or variable?
8.Whether diplopia worsens at the end of the day?
9. History of any trauma to eye, face, head or any
history of ocular surgery recent or in past.
10. Detailed history of systemic diseases like
diabetes mellitus, hypertension, thyroid
disorders, myasthenia gravis should be taken.
17. Leading questions
In which direction of gaze are the images
maximally separated?
Diplopia is maximum ( separation of images)
in the field of action of the paralysed muscle.
To which eye does the “outer” image belong?
The false image ( the image belonging to the
eye with the hypofunctioning muscle ) is
always peripherally situated
18. Clinical Evaluation
For monocular diplopia
Pin hole test
Refraction
Anterior segment examination with slit lamp
Detail fundus examination for retinal
disorders
19. The evaluation of binocular
diplopia
1. Abnormal head posture
2. Orbital and lid abnormalities
3. Extraocular muscle movements
4. Pupillary reactions
5. Neuromuscular junction examination (M.G)
6. Examination of cranial nerves especially
third, fourth and sixth cranial nerves
20. The evaluation of binocular
diplopia
7. Prism Bar CoverTest
8. Maddox rod test
9. Double Maddox RodTest
10. Diplopia charting (R/G goggles)
11. Paretic vs restrictive etiology
12. HessTest
13.Worth four light test
21. Diplopia Charting
This test helps in recording the subjective
deviation by asking the patient to quantify
the separation between the double images,
dissociated by red green glasses.
Main points to be remembered are:
a. Maximum separation is in the quadrant in
which the muscle acts most (field of action)
b.The image that appears farthest, belongs to
the deviating eye
c.The image is displaced in direction of action
of paralysed muscle.
22.
23. 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.
24. Interpretation
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
25. Systemic Investigations
1. Blood sugar levels / HbA1C for Diabetes
Mellitus
2.Test for myasthenia gravis –
electromyography (EMG), nerve conduction
studies with a repetitive stimulation test and
anti - acetylcholine receptor antibodies
3.T3,T4,TSH for thyroid eye disease
4. CT scan / MRI of brain and orbit for thyroid
eye disease, any intracranial or orbital
pathology.
26. Treatment
1. Treat the underlying cause, wherever possible.
2. Correction of refractive errors if present.
3. Unilateral eye occlusion therapy with either an
eye patch or by blurring one lens of the patient’s
glasses with semi-opaque surgical tape.
4. Prisms are used for optical correction of
symptomatic binocular diplopia.
5. Orthoptic exercise (CI)
6. Surgery for strabismus can be done to restore
ocular alignment after a period of observation
for at least 06 months.