This document discusses the case of a 25-year-old male presenting with double vision since 2 months following a head trauma. On examination, he was found to have a left eye esotropia with an abduction deficit grade of 4, indicating a left sixth nerve palsy. Sensory testing showed binocular uncrossed diplopia maximum in left gaze. The patient was diagnosed with an acquired post-traumatic left sixth nerve palsy. He was initially managed conservatively with fogged glasses with regular follow-up to monitor recovery.

1. Presenter – Dr. Bikram B Thapa
Moderator – Dr. Savleen Kaur
Chairperson – Dr. Jaspreet Sukhija

2. Aim
To discuss a case of traumatic sixth nerve palsy and its
management.

3. Chief complaints
25 year male DOP 04.07.2014
C/o double vision since 2 months.

4. History of presenting illness
History of double vision since 2 months
Sudden in onset
Disappears on closing one eye
Present in primary and left lateral gaze
Constant in nature - No diurnal variation
Associated with inward deviation of left eye and inability to
move left eye outward
constant deviation, not progressed/improved

5. Past history
A H/O fall from moving train 2 months back when he
sustained injury to left side of the head
H/O loss of consciousness, admitted and treated outside
conservatively
CT scan showed multiple parietal bone fractures with temporo-
parietal extra-dural haematoma.

6. No h/o similar complaints in the past
No h/o prior ocular surgery
No h/o any systemic illness
No h/o squint in family
No h/o treatment taken

7. Examination (04.O7.2014)
OD OS
Visual acuity 6/6 6/6
IOP 10 mm Hg 12 mm Hg
Lids and adnexa WNL WNL
EOM Photos Photos
Anterior segment WNL WNL
Posterior Segment WNL WNL

8. Squint examination
Head posture: face turn to
left

9. Measurement of ocular deviation
Hirschberg test
Reflex in L/E falls at the pupillary margin
on temporal side indicating 15 degrees of
esotropia in LE

10. Cover test Video

11. Extra-Ocular movements: versions

12. LIMITED
LIMITED
DUCTIONS- ocular movements remained the same with
no improvement in abduction
LIMITED

13. Abduction deficit grade -4
GRADES:
• -1= can rotate eye from midline to 75% of full
rotation
• -2= can rotate eye from midline to 50% of full
rotation.
• -3= can rotate eye from midline to 25% of full
rotation
• -4= can rotate eye upto midline but not
beyond it
• -5= cannot rotate eye from opposite field to
midline
Scott AB Kraft SP Botulinum toxin injection in the management of
lateral rectus paresis. Ophthalmology. 1985;92676- 683

14. Prism Bar Cover Test ( primary deviation)
for near and distance
0 35 BO 45 BO
0 35 BO 45 BO
0 35 BO 45 BO
ALL VALUES IN PRISM DIOPTERS

15. PBCT (secondary deviation) for near and
distance
0 45 BO 55 BO
0 45 BO 55 BO
0 45 BO 55 BO
ALL VALUES IN PRISM DIOPTERS

16. SENSORY EVALUATION

17. Worth 4 dot test – distance and
near
2 RED AND 3 GREEN seen simultaneously s/o Diplopia

18. Diplopia charting Red- RIGHT EYE
Green LEFT EYE
AS THE PATIENT SEES IT at 1 m; uncrossed horizontal diplopia
maximum diplopia in Left lateral gaze; distal image belongs to left eye
BSV1 INCH
2
INCHES
L R

19. Stereopsis
Titmus fly test
Couldn’t appreciate flying wing of titmus fly s/o
Absence of gross stereopsis

20. SUMMARY
25 Yr male with h/o head trauma followed by diplopia
since 2 months. VA was 6/6 with normal anterior and
posterior segment both eyes. Left eye showed an
esotropia with abduction deficit grade 4. Primary
Deviation measured was 35 PD and secondary deviation
was 45 PD esotropia in primary gaze by PBCT. Diplopia
charting showed binocular uncrossed horizontal
diplopia, maximum in left lateral gaze. Sensory
examination showed diplopia on Worth four dot test and
absence of gross stereopsis.

21. CLINICAL DIAGNOSIS
Left Eye ACQUIRED (POST TRAUMATIC) SIXTH
NERVE PALSY
Right Eye WNL

22. TESTS OF MUSCLE FUNCTION
Forced Duction Test : Negative for medial rectus left
eye (No Medial rectus contracture present)
Force Generation Test : FOR left eye lateral rectus –
Weak generated force

23. Final diagnosis
L/E Acquired post traumatic sixth nerve palsy with no
secondary medial rectus contracture

24. Management
Conservative management
Right eye fogged glasses for working hours
Used in front of the normal eye so as to stimulate
movement of the paretic and thus prevent the
development of contracture of the antagonist.
On regular follow up.

25. Follow up
1. Whether diplopia is improving or worsening.
2. Amount of esotropia ( increasing or decreasing).
3. Grade of abduction limitation
4. Any new neurological symptom or sign.
5. Compliance to the treatment given.

26. Course of post traumatic sixth nerve palsy
Overall recovery 73-83% at the end of 6 months
(unilateral 84%, bilateral 38%)
Recovery rate related to severity at initial examination
The median time to recovery is 90 days
Upto 3% may require surgery
Holmes et al.J AAPOS 1998;2:265-8

27. Predictors of non recovery
Nonrecovery - presence of diplopia in primary position or
more than 10 prism diopters of esotropia in primary
position, at 6 months from onset.
1. Complete paralysis (inability to abduct till midline;
abduction deficit grade -4 or -5)
2. Bilateral involvement
Holmes et al. Ophthalmology 2001;108:1457–1460

28. Indications of neuroimaging in traumatic
sixth nerve palsy in adults
1. At the first visit
2. Progression in esotropia
3. Diplopia worsening.
4. Presence of additional neurologic signs or symptoms.
Goodwin et al. Optometry 2006;77:534-539

30. Trauma as cause of six nerve palsy
Etiologies of acquired VI nerve palsy
Schrader
et al
Rucker
et al
Johnston
et al
Robertson
et al
Rush
et al
Potel
et al
Bagheri
et al
Trauma 3% 12% 32% 20% 17% 12% 18%
neoplasm 7% 33% 13% 39% 15% 5% 2%
Aneurysm 0 3% 1% 3% 3% 2% 0
Ischemia 36% 8% 16% 0 18% 16% 1%
Miscellaneo
us
30% 24% 30% 29% 18% 19% 6%
Undetermin
ed
24% 20% 8% 9% 29% 26% 6%
Miscellenious = migraine, multiple sclerosis, pseudotumor cerebri as non localising
sign
Azarmina et al.J Ophthalmic and vision research 2013;8:160-171

31. Causes of 6th nerve palsy in trauma
The abducens nerve is particularly vulnerable to
trauma because of its long intracranial course.
At the apex of the petrous part of the temporal
bone. It may be stretched as it passes from the
brainstem to its entry to the dura at the basilar process
by downward and forward displacement of the brain
stem.
Fracture of the cranial floor causing compression
on nerve
Meningeal oedema, or
Inflammation in the skull base.
Hollis et al. J Accid Emerg Med 1997;14:172-175

32. PLAN OF MANAGEMENT
Tests of muscle function- to identify medial rectus contracture
Fracture of left
parietotemporal bone
Biconvex hyperdense
lesion
Just beneath the
fractured bone
s/o extradural

33. Non surgical therapy
Prisms-
Deviation of 10-15 PD can easily be corrected by
prisms.
Fogged glasses
With large angle incomitance where it can not be
corrected by prisms.
Used in front of the normal eye so as to stimulate
movement of the paretic and thus prevent the development
of contracture of the antagonist.

34. Surgical therapy
Indications:
If paralysis is of recent onset, 6-8 months of waiting
period is mandatory for the condition to be considered
stable.
During the waiting period patient is evaluated at frequent
intervals and visual comfort maintained with prisms or
unilateral occlusion

35. Discussion
Paralytic Non paralytic
Age of onset late childhood
Type of onset sudden gradual
Inciting causes Head trauma, systemic illness absent
Diplopia present absent
Head posture present absent
Incomitance present absent
Limitation of movement present absent
Difference in primary and
secondary deviation
present absent
Sensory adaptation absent present
Sixth nerve palsy has been reported to be the most common type of extra
ocular nerve paralysis
Rush JA, Younge BR. Arch Ophthalmol1981;99:76-79

36. Surgeries of paretic muscle
Botulinum toxin injection in the antagonist. Recovery rate
at 6 months is as same as conservatively managed patients
(73% versus 71% in the conservatively managed group)
LR resection with MR recession. Recession of the
contralateral MR is often needed to increase the diplopia
free field and to reduce incomitance.

37. Surgeries of the paralytic muscle
Treated with vertical rectus transposition procedures
combined with MR recession.
Increased risk of anterior segment ischaemia.
20-30% risk of vertical misalignment.

38. Surgical options for sixth nerve
palsyUnilateral recession and resection
Unilateral recession and resection with contralateral
MR recession.
Single muscle recession/resection upto 20 PD
Unilateral recession resection upto 40 PD
Larger deviation>40 PD= Combine with C/L MR recession
ADV: Easy to perform/no risk of ant seg. ischemia
DISADV: binocular fields reduced ; undercorrection

39. Partial vertical rectus transposition +MR weakening
(HUMMELSHEIM PROCEDURE)
Full vertical rectus transposition +MR weakening ( O’
Conner)
Rectus muscle union + MR weakening (JENSEN)
Combine with MR recession if ET>25 PD
ADV: Improves abduction; when R-R fails
DISADV: Ant seg ischemia; overcorrection

40. Limited
abduction
Duction upto
midline
Force
generation test
no force
transposition
Mild to
Moderate force
Recession/resection
Duction past
midline
Recession/resection

41. INCOMITANT STRABISMUS
: CLASSIFICATION AND INVESTIGATION
Definition:a strabismus where the angle or degree of
the deviation varies in different directions of gaze OR
with each eye fixing (ie the secondary deviation is
greater than the primary deviation).

42. Paralytic strabismus –clinical
features
Incomitance
Limitation of movement of eye in the field of action of
extraocular muscle
Secondary deviation greater than the primary
deviation

43. Inclusion criteria
1. Initial examination _<2 months after injury
2. Inability to fully abduct 1 or both eyes
3. History of head trauma
4. Diplopia in primary position
5. Visual acuity _>20/200 in each eye
6. Distance esotropia at least >10 PD
7. Absence of a third nerve palsy
8. Absence of treatment with botulinum toxin or surgery
TABLE 2. Patient demographics, palsy characteristics, and recovery
rates
All Unilateral Bilateral
palsies palsies palsies
1. Number of patients 33 25 8
2. Median age (y) 20 18 22.5
3. Complete palsy 16 (48%) 10 (40%) 6 (75%)
4. Median severity of NA -3 -8
abduction deficit
5. Spontaneous recovery 24 (73%) 21 (84%) 3 (38%)
6. Median time to 91 90 92
documented recovery (d)