16 superior oblique palsy

Diagnosis and Management of Superior Oblique Palsy

1. Diagnosis and
Management of
Superior Oblique Palsy
Pediatric Ophthalmology
LSU Medical Center
Shreveport

2. Superior Oblique Palsy
Most common cause of:
Congenital Vertical Deviation
Acquired Vertical Deviation

3. Anatomy: Superior
Oblique

4. Function: Superior
Oblique

5. Functions of Superior
Oblique
Depression
Greatest in adduction
Incyclotorsion
Greater in down gaze and abduction
Abduction
Primarily in down gaze

6. SO Palsy Results In:
Hypertropia
Greater in adduction
Excyclotorsion
Greater in down gaze and abduction
Esotropia
Primarily in down gaze
“V” pattern
Primarily in bilateral SO palsy

7. Causes of SO Palsy
Congenital or childhood onset
Head tilt may appear by age 2-4 months
May cause facial asymmetry
Deviation may not be noted until adulthood
Acquired
Closed head trauma (most)
Vascular disease
Neoplasm
Inflammation (e.g. temporal arteritis)

8. Systemic Workup of SO
Palsy
Usually unrewarding if SO palsy
isolated (i.e., no other new ocular or
neurologic signs or symptoms)
Definitely not needed if signs of
childhood onset present

9. Evolution of New SO
Palsy
Initially:
Vertical deviation greatest in field of SO
(i.e., gaze down and in)
Later
Contracture of antagonist and changes in other
vertical muscles often occurs
Vertical deviation often greater in other fields of
gaze

10. Spread of Comitance in
SO Palsy

11. Knapp’s Classification
of SO Palsy

12. Torsional Diplopia in SO
Palsy
Eye itself is extorted
Visible on fundus exam
Superior pole of image seen by patient
appears intorted
If normal eye is occluded and patient
asked to hold object straight, he will
hold it in an extorted position

13. Fundus Torsion

14. Fundus Torsion
Indirect
Ophthalmoscope View

15. Diplopia in SO Palsy
Diplopia may be vertical, torsional
and/or horizontal
Occasionally, torsional diplopia occurs
with little or no vertical deviation
Bilateral SO palsy: large amount of
torsional diplopia, no vertical deviation
in primary if bilateral palsy symmetric

16. Signs and Symptoms of
SO Palsy
Diplopia
Torticollis
Strabismus

17. Torticollis in SO Palsy
Classical:
Head tilt to normal side
Face turn to normal side
Chin down
Not stereotyped: variations exist
Head tilt may be “paradoxical”: i.e. to side
of paretic eye

18. Torticollis In SO Palsy
Torticollis may be large and noted at
age 2-4 months of age
Head tilt may be small and not noted by
patient
Old pictures (or spouse) helpful

19. Torticollis in SO Palsy

20. Torticollis in SO Palsy

21. Facial Asymmetry in SO
Palsy

22. Ocular Rotations in SO
Palsy
Over 50%: no overt weakness of SO
Eye appears to move down and in normally
May look like palsy of contralateral SR
(if patient fixates with paretic eye in
adduction, non paretic eye will be
hypotropic)
Called inhibitional palsy of contralateral
antagonist of Chavasse

23. Park’s Three Step Test
for Diagnosis of SO
Palsy
Often needed since diagnosis often not
clear from versions and ductions
Often cannot localize weak muscle from
rotations (ductions and versions)

24. Step One
Cover test in primary gaze
Determine if RHT or LHT present in
primary gaze
E.g. RHT would mean either:
Weak right depressor: RIR or RSO, or
Weak left elevator: LSR or LIO

25. Park’s Three Step Test
Provides reliable information only if an
isolated palsy of a cyclovertical muscle
is present
Not helpful in other conditions, such as:
DVD
Thyroid eye disease
Brown’s syndrome
Blowout fracture with entrapped IR

26. Park’s Three Step Test:
Step Two
Perform cover testing in right and left gaze
Determine if HT greater in right or left gaze
E.g., RHT worse in left gaze:
Indicates weak RSO or weak LSR
Deviation greater when optical axis aligns with
angle of muscle from origin to insertion

27. Park’s Three Step Test
Step Three
Step three is Bielschowsky head tilt test
Measure deviation in right head tilt and
left head tilt
Determine if deviation greater in right
head tilt or left head tilt

28. Head Tilt Test
If a superior muscle is weak, HT greater
on tilt toward involved muscle
If an inferior muscle is weak, HT greater
on head tilt opposite involved side

29. Head Tilt with No
Muscle Palsy

30. Head Tilt in RSO Palsy

31. SIN: Superior Muscles
Intort
Superior Oblique and Superior Rectus
are both intorters
Inferior Oblique and Inferior Rectus are
both extorters

32. Head Tilt Test
After step one and step two in Park’s three
step test, one is always left with two muscles
Either two superior muscles or
Two inferior muscles
E.g.,
RSO or LSR
LSO or RSR
LIO or RIR
RIO or LIR

33. Head Tilt Test
Step Three:
E.g., RHT worse on left gaze
 After two steps, means either weak RSO
or weak LSR
HT worse on right head tilt: RSO palsy
HT worse on left head tilt: LSR palsy

34. SO Palsy: Chart to
Memorize

Hypertropia


Gaze
where HT
larger
Head Tilt
where HT
larger
RSO
Palsy
R L R
LSO
Palsy
L R L

35. Other Ways to Diagnose
SO Palsy
Red lens or Red Maddox rod over one eye
Red lens: fixate on a letter
Maddox rod: fixate on a bright light
Measure subjectively in:
Right and left gaze
Right and left head tilt
Very helpful for small acquired deviations

36. Bilateral SO Palsy
V pattern with esotropia in downgaze
common
Excylotorsion over 10-15 degrees
HT changes from right to left gaze
E.g., RHT on left gaze, LHT on right gaze
Type of HT changes on head tilt
E.g., RHT on right head tilt, LHT on left
head tilt

37. Bilateral SO Palsy
Vertical deviation often asymmetric
If symmetric, little or no vertical in primary gaze
Often first diagnosed after surgery for
apparent unilateral SO palsy (called “masked
bilateral SO palsy”)
Double Maddox Rod helpful to diagnose pre-
operatively

38. Measurement of Torsion
Double Maddox rod placed in trial frame
One red, one white (or two red Maddox rods)
Patient views a single white light source
Patient sees a red line and a white line
Rotate one lens to make the two lines parallel
(subjectively)
Use vertical prism if needed to separate lines

39. Double Maddox Rod to
Measure Torsion

40. Treatment of SO Palsy
Surgical Treatment
Non-Surgical Treatment

41. Non Surgical Treatment
of SO Palsy
Wait six months if new palsy occurs
Many improve spontaneously
Patch for diplopia
Let adult choose which eye to patch, usually non
paretic eye
Prisms
May be helpful in adults with diplopia and with
smaller less incomitant deviations
Amblyopia
Treat if present
May occur in either eye

42. Indications for Surgery
Strabismus
Noticeable or bothersome to patient
Head tilt
Noticeable or bothersome to patient
Diplopia

43. Which Muscle to
Operate On
Measure vertical deviation in all fields
Pay particular attention to:
Primary gaze
Right and left gaze
Oblique gazes opposite palsy

44. Important Fields of Gaze

45. Surgery for SO Palsy
Surgery planned primarily based on the
deviation and where the deviation is
largest
Head Tilt primarily useful for diagnosis
Presence of bilateral SO palsy will
change treatment plan

46. Surgical Treatment of
SO Palsy
Some patients, mostly childhood onset
types, have laxity in the SO tendon
Found with forced duction of SO under
general anesthesia
Patients with laxity of SO tendon need
SO surgery (generally SO tuck) to
equalize forced duction with normal SO

47. Surgical Treatment of
SO Palsy
Superior Oblique tuck performed on
patient without laxity in the tendon likely
to cause a “Brown syndrome”, or
inability to look upward in adduction
SO tuck still often indicated in:
SO palsy worse in straight down gaze
Bilateral SO Palsy

48. Bishop Tendon Tucker

49. Surgical Treatment of
SO Palsy
Patients without laxity of SO, primary
surgical procedure is weakening
(generally recession) of IO, the direct
antagonist to the weak SO
Unilateral cases
IO weakening done in 50-80% of cases
Can be done with adjustable suture

50. Surgical Treatment of
SO Palsy
If deviation greatest in field of SO and
no tendon laxity present, choices are:
Weaken opposite inferior rectus
Tuck SO
Which muscle depends on difference of
deviation in primary and lateral
gaze,and down and down and lateral
gaze

51. Surgical Treatment of
SO Palsy
Recess ipsilateral superior rectus if:
Positive forced duction on attempted
depression of paretic eye
Five diopter or more vertical in abduction of
paretic eye

52. How Many Muscles to
Operate on
Determine deviation in field of greatest
deviation
If that deviation is under 15-20 diopters,
operate on one muscle
If that deviation is over 15-20 diopters,
operate on two muscles
Three muscles: usually results in
overcorrection

53. IO Weakening
Amount of correction varies with
amount of overaction of IO
Can correct 10-15 diopters in primary
gaze
Can be done as adjustable suture in
adults

54. Treatment of Bilateral
SO Palsy
Mostly torsional with little vertical
deviation: Harada Ito procedure
With large HT in side gaze: tuck SO OU
Usually bilateral IO overaction not seen

55. SO Tuck: Dangers
Can easily overcorrect and create
restriction if SO tendon is not lax
In the past, large percentage of SO
tucks had to be “taken down”
Use forced ductions at surgery as guide
to amount of tuck

56. Other Surgical
Complications
IO weakening
Can cause “ adherence syndrome” if fat pad
penetrated: will look like IO overaction on other
side (restriction of elevation in abduction of
operated eye)
IR Recession
Can easily cause lower eyelid retraction
Can prevent eyelid retraction with recession of lower lid
retractors

57. Amount of Surgery
IO weakening
Recess to just posterior and lateral to IR
insertion
Can do asymmetric IO recession OU
SO tuck
Determine at surgery
Usually 6-14 mm, sometimes more

58. Amount of Surgery
IR Recession
Usually 3-5 mm: use adjustable suture in
adults
SR Recession
Usually 3-5 mm: use adjustable sutures in
adults

59. Work Up of SO Palsy
History
Trauma
Diplopia
Torticollis
Other neurological signs or symptoms

60. Work Up of SO Palsy
Observe torticollis
Measurement in all cardinal fields and
head tilt right and left
Double Maddox Rod to measure torsion
Observe fundus for torsion

61. SO Palsy with Torsion
and No Or Minimal HT
Tuck or advance anterior portion of SO
tendon
Advancement of anterior SO called
Harada Ito procedure

62. Harada Ito Procedure

63. Canine Tooth Syndrome
Trauma to SO tendon
Results in SO palsy with poor elevation
in adduction (“ Brown’s syndrome”)
Rx: difficult
Free restrictions
Weaken yoke IR

64. Canine Tooth Syndrome

65. Types of SO Palsy
Childhood
Onset
Adult Onset
Size of
deviation
Large Small
Fusional
Vergence
Large Small
BilateralityAlmost never 25%
Diplopia Rare Always
Usual Rx Weaken IO, +/-
SO tuck
Recess IR

66. Course of SO Palsy
May present early in childhood with
torticollis or strabismus
May present later ( often age 30-50)
with symptoms from strabismus or
torticollis

67. Field of Single Vision
Very important to patient
Often ignored by physician
Measure pre-op and post-op ( can use
Goldman perimeter) or estimate
Warn patients that deviation will
probably be present in some fields post-
op