1. Special Forms of Strabismus
Abbas Attarzadeh MD
Professor of ophthalmology
SUMS

2. Duane Syndrome
Retraction of the globe in actual or attempted adduction.
Horizontal eye movement is usually somewhat limited in both directions.
Upshoot or downshoot (leash phenomenon)
of the affected eye in attempted adduction
co-contraction of the medial and lateral rectus muscles
and, alternatively, to slipping of the lateral rectus muscle over the outer aspect of the eye.

4. Most cases of Duane syndrome are sporadic
5%-10% show autosomal dominant inheritance
A higher prevalence in females

5. In most anatomical and imaging studies, the nucleus of the sixth cranial nerve is absent, and an aberrant branch of the third cranial nerve has innervated the lateral rectus muscle

6. Electromyographic studies have shown:
paradoxical innervation of the lateral rectus muscle (innervation on attempted adduction and reduced innervation on attempted abduction).
Anomalous synergistic innervation of the medial, inferior, and superior rectus muscles and the oblique muscles

7. Although considered an innervational anomaly: Tight and broadly inserted medial rectus muscles Fibrotic lateral rectus muscles, with corresponding forced duction abnormalities, are often encountered at surgery.

8. Clinical Features
Poor abduction, frequently with primary position esotropia
Poor adduction and exotropia
Poor abduction and adduction, with esotropia, exotropia, or no primary position deviation
50%-80% in several series
About 15% of cases are bilateral;

9. DDX with sixth nerve palsy
Careful observation for globe retraction on adduction
lack of correspondence between the absent or typically modest primary position esotropia and the usually profound abduction deficit
A further point of differentiation is that, even in esotropic Duane syndrome, a small-angle exotropia frequently is present in gaze to the side opposite the affected eye

10. Management Indications for surgery
Primary position deviations
Abnormal head position
Marked globe retraction
Large upshoots or downshoots

11. Duane syndrome with esotropia
Recession of the medial rectus muscle on the involved side
Bimedial rectus recession recommended for deviations over 20∆ in primary position
Resection of the lateral rectus muscle for Duane syndrome with esotropia is not favored
because of the likelihood that globe retraction will worsen,
although one study
reported favorable results with unilateral recession-resection procedures

12. Bimedial Rectus Recess

13. Partial or full transposition of the vertical rectus muscles has been advocated to improve abduction but may exaggerate the effects of co-contraction.
Posterior scleral fixation of the transposed
portions of the vertical rectus muscles, as described by Foster, has been found helpful,
no only in Duane syndrome but in several types of paralytic strabismus as well

14. Surgery

15. The value of botulinum injection into the medial rectus muscle to improve abduction is controversial

16. Duane syndrome with exotropia and deficient adduction (type 2)
Recession of the lateral rectus on the involved side for small deviations
Both lateral recti for large deviations
with avoidance of resection of the medial rectus
The latter aspect is especially
important when an up- or downshoot is present on attempted adduction, because this
finding indicates severe co-contraction

17. type 3 Duane syndrome who have poor abduction and adduction
Have straight eyes in or near the primary position and little, if any, head turn
Severe globe retraction may be helped by:
Recession of both the medial and the lateral rectus muscles
Splitting the lateral rectus muscle in a Y configuration
A posterior fixation procedure on LR
Disinsertion of the lateral rectus muscle and reattachment to the lateral wall of the orbit is the most recent procedure to be tried

18. LLR recess 13 mm + Bifurcation
LMR Bifurcation

19. Brown Syndrome

20. Shortening of the anterior sheath of the superior oblique tendon.
Brown syndrome was described by Harold W. Brown in 1950 as the superior oblique tendon
sheath syndrome.
restriction of elevation in adduction
Shortening of the anterior sheath of the superior oblique tendon.
Restriction of the superior oblique tendon at the trochlear pulley
abandoned this theory

21. Brown Syndrome
Restriction of the superior oblique tendon at the trochlear pulley

22. Brown syndrome Congenital Acquired form
bilateral in approximately 10% of cases
Congenital
Acquired form
Trauma in the region of the trochlea
Systemic inflammatory
Resolution of congenital Brown syndrome is unusual but possible
intermittent Brown syndrome, which may resolve
spontaneously.

23. Comparison of Inferior Oblique Muscle Palsy With Brown Syndrome
Deficient elevation in adduction that improves in abduction but often not completely
Inferior Oblique Muscle Palsy
Brown Syndrome
Forced ductions
Negative
Positive
Strabismus pattern
A pattern
V pattern
Superior oblique muscle overaction
Usually present
None or minimal
In adduction, the palpebral fissure widens and a downshoot of the involved eye is often seen; it can be distinguished from superior oblique muscle overaction because downshoot in the latter condition occurs less abruptly as adduction is increased.

24. Brown syndrome OS Divergence in upgaze
Down shoot in attempted elevation in adduction?
Down shoot in attempted elev. in adduct. (different than IO palsy)

25. Brown syndrome mild moderate severe hypotropia in primary position no
yes
downshoot of the eye in adduction.
chin-up head posture and sometimes by a face turnaway
from the affected eye insever cases

26. in adduction is essential for the diagnosis of Brown syndrome.
An unequivocally positive forced duction test demonstrating restricted passive elevation
in adduction is essential for the diagnosis of Brown syndrome.
Retropulsion of the globe
during this determination stretches the superior oblique tendon and accentuates
the restriction.
When inferior rectus muscle fibrosis or inferior orbital blowout fracture
(the principal entities to be differentiated) produces a restrictive elevation deficiency,
the limitation to passive elevation is accentuated by forceps-induced proptosis of the eye rather than by retropulsion.

27. Management
Observation alone in about two thirds of all Brown syndrome cases
rheumatoid arthritis or other systemic inflammatory diseases
Systemic treatment
Corticosteroids injected near the trochlea
Sinusitis has also led to Brown syndrome
CT of the orbits and paranasal sinuses

28. Surgical treatment is indicated for the most severe cases
Primary position hypotropia
Anomalous head posture
Iatrogenic superior oblique muscle palsy may occur postoperatively. 44%-82%
sheathectomy
has been abandoned in favor of ipsilateral superior oblique tenotomy

29. Brown Syndrome SO tenotomySR SR LR RM MR LR IR IR IO IO

30. Superior oblique muscle palsy
Reduced: By careful preservation of the intermuscular septum during tenotomy. This modification often produces an early under correction that gradually improves with time

31. Perform simultaneous ipsilateral inferior oblique muscle weakening.
guarded tenotomy using an inert spacer sewn to the cut ends of the superior oblique tendon
Controlling the gap between the cut ends with an adjustable suture
These procedures eliminate the need for simultaneous inferior oblique muscle
weakening but sometimes result in a downgaze restriction due to adhesions to the nasal
border of the superior rectus muscle. Care must be taken to avoid contact of the spacer to
nearby structures by preserving the intermuscular septum

32. For those surgeons who are a little too chicken to completely cut the SO tendon and cause a SO palsy… Chicken suture technique

33. Brown Syndrome Chicken suture

34. For those surgeons with a sense of humor… Try the rubber chicken trick aka silicone expander

35. Brown Syndrome Silicone expander

36. Facia Lata

37. Third Cranial (Oculomotor) Nerve Palsy

38. Traumatic 3rd N palsy

39. The causes of third cranial nerve palsy in children
Congenital disorders (40%-50%)
Trauma
Inflammation
Viral infection
Migraine
(Infrequently) neoplastic lesions
Adults
Intracranial aneurysm
Diabetes,
Neuritis
Infection
Rarely, tumor
Diabetic third cranial nerve palsy generally resolves spontaneously within 3-4 months.
The majority of adults referred for surgical treatment have palsy due to trauma

40. Clinical Features Limited: Adduction Elevation Depression
Exotropia and often Hypotropia
Upper lid ptosis usually is present, often with a pseudoptosis

41. Aberrant regeneration (misdirection)

42. Niknam Farshad 23 yo accident 4years ago 3rd nerve palsy aberrant regeneration

43. Management
Except in congenital cases of third cranial nerve palsy, it is advisable to wait 6-12 monthsfor any spontaneous recovery before surgical correction is planned.
Patients with at least
partial recovery are much better candidates for good functional, as well as cosmetic, results,

44. Cured III N palsy

45. Third cranial nerve palsies present difficult surgical challenges because multiple extraocular muscles as well as the levator may be involved.
Replacing all of the lost rotational forces on the globe is impossible; therefore, the goals of surgery must be thoroughly discussed
With patients so their expectations are realistic, Adequate alignment for binocular function in primary position and in slight downgaze for reading may be all that can be expected.

46. Sadravy Bahareh post surgery rt 3rd N palsy 15 years po 9.3.86

47. surgical procedure
A large recession-resection procedure on the horizontal rectus muscles to correct the exodeviation, with supraplacement of both to correct the hypotropia
Most surgeons reserve correction of ptosis for a subsequent procedure
Some surgeons use superior oblique tenotomy instead of supraplacement of the horizontal rectus muscles for hypotropia

48. Sixth Cranial (Abducens) Nerve Palsy
Sixth nerve palsy.ppt

49. Graves Eye Disease
motility disturbances

50. Edema, inflammation, and fibrosis are present in this disease because of lymphocytic infiltration. These conditions result in massive enlargement of affected extraocular
muscles and may not only restrict motility but also cause compressive optic neuropathy.

52. Detection of this muscle enlargement by orbital ultrasound, CT, or MRI helps confirm the diagnosis of Graves eye disease.

53. The myopathy is not caused by thyroid dysfunction
Some patients with Graves disease also have myasthenia gravis
It is mostly a disease of adults but can occur in children.

54. Clinical Features
Severe restrictive, The muscles affected, in decreasing order of severity and frequency:
inferior rectus
medial rectus
Superior rectus
lateral rectus
The condition most often is bilateral and asymmetric.
Forced duction test results are almost always positive in 1 or more directions.

55. Upper eyelid retraction often is present.
The patient presents most often with some degree of proptosis, hypotropia, or esotropia
Upper eyelid retraction often is present.
Graves eye disease is a common cause of acquired vertical deviation in adults, especially females, but is rare in children

56. Management Indications for strabismus surgery: Diplopia
Abnormal head position
Surgery may eliminate diplopia in primary gaze but rarely restores normal motility

57. waiting for at least 6 months is recommended.
It is important to establish stability of the strabismus measurements before surgery is performed
waiting for at least 6 months is recommended.
Half of the patients required repeated operation
Strengthening
procedures are rarely performed because they usually worsen restriction

58. Adjustable sutures are helpful in these difficult cases.
Slight initial undercorrection is desirable, because late progressive overcorrection is common, especially with large inferior rectus recessions.
Nonabsorbable sutures may decrease the likelihood of overcorrection.
Limited depression of the eyes after inferior rectus muscle recessions can interfere with bifocal use by patients
Proptosis can become worse after extraocular muscle recessions.

59. Hint
If the need for orbital decompression is foreseeable, it is usually preferable to postpone strabismus surgery until that has been accomplishe
Likewise, eyelid surgery usually is performed at a later time because upper eyelid retraction may be improved when the patient no longer strains to elevate the eye lid

60. Large recessions of very tight inferior rectus muscles can cause lower eyelid retraction severe enough to require subsequent eyelid surgery. Severing the lower eyelid retractors
as part of the strabismus surgery has led to some success at preventing this complication.
If necessary, a spacer of banked sclera or synthetic material can be placed to vertically
lengthen the lower lid tarsus

61. Which patients require surgery?
Emergent basis
optic nerve compression
corneal exposure
Non emergent
severe disfiguring proptosis
double vision from restrictive myopathy
eyelid retraction

62. What kinds of surgery are done in patients with TRIO?
Orbital decompression
Eye muscle surgery
Eyelid surgery
needs to be done in this order
Decompression affects ocular motility and may alter muscle surgery
muscle surgery should be completed before eyelid surgery

63. Which patients require orbital decompression?
Optic nerve compression :
EOM swelling with relatively little space at the apex of the orbit
squeezing of the optic nerve at the apex of the orbit
Severe proptosis resulting in corneal exposure or disfigurement

65. When do patients require muscle surgery?
Double vision in functional field
Ensure that the inflammation is quiet and the patient's motility pattern is stable
Repeated stable measurements over 6+ months help to ensure that motility is stable

66. What are the alternatives to muscle surgery?
prisms in glasses works for patients with double vision and relatively small deviations
It is better that the motility become stable before prisms are prescribed
Temporary Fresnel prisms may be helpful during periods of instability

67. Botulinum toxin A injection has a good effect in the treatment of restrictive strabismus in TAO.
Early treatment has better results.
Dosage in TAO is higher, the mean changes of degree of deviation is slighter, the interval between injections and the duration of effect is shorter.
Injection dosage should increase after repeated injections.

68. What type of muscle surgery is required?
Recession of muscles, usually on an adjustable suture basis
Muscles are tight and scarred, resection is not indicated
Inferior and medical rectus muscles are the most common targets
Forced duction test at the time of surgery is indicated

69. Does eye muscle surgery affect the eyelids?
Recession of the tight IR
often improves upper eyelid retraction:
SR had to work against the tight IR, thus the associated levator muscle was overactive, causing eyelid retraction. When the IR is recessed, the overactivity relatively ends
Large recession of IR may worsen inferior lid retraction

70. What kind of eyelid surgery is done?
Eyelid retraction
Orbital decompression lowers eye, improving the lower lid retraction
Mild lid retraction: recession of the eyelid retractors (upper or lower) is adequate
Severe retraction: spacers are needed, such as hard palate in the lower lids and fascia in the upper lids
Blepharoplasty and/or brow lift
Excessive skin from chronic swelling
At the same time or later date

72. How many surgeries do patients with TRIO require?
Most do not require surgery
Patients who need surgery may need from 1 to as many as 8-10 times over 2-3 years of reconstruction

73. Chronic Progressive External Ophthalmoplegia

74. Clinical Features
Chronic progressive external ophthalmoplegia (CPEO) usually begins in childhood
with:
Ptosis
Slowly progresses to total paralysis of the eyelids and extraocular muscles

75. CPEO may be sporadic or familial.
Although a true pigmentary retinal dystrophy usually is absent, constricted fields and electro diagnostic abnormalities can occur.

76. Defects in mitochondrial DNA have been found in some patients.
The triad of :
Retinal pigmentary changes
CPEO
Cardiomyopathy (especially heart block)
is called Kearns-Sayre syndrome

77. Management
Treatment options are limited. Cautious surgical elevation (suspension) of the upper eyelids indicated to lessen a severe chin-up head position.

78. Myasthenia Gravis

79. Myasthenia Gravis
Onset of myasthenia gravis may occur at any age but is uncommon in children.
A transient neonatal form, caused by the placental transfer of acetylcholine receptor antibodies of mothers with myasthenia gravis, usually subsides rapidly.
Another variety is not immune mediated and exhibits a familial incidence.

80. The disease may be purely ocular
(30%-50%) occurs as part of a major systemic disorder
Childhood myasthenia gravis is more common in females.

81. Clinical Features
The principal ocular manifestation is extraocular muscle weakness, including weakness of the levator muscle.
The majority of cases (90%) have both ptosis and limited ocular rotations.

82. Ptosis typically increases when the patient is
required to look upward for 30 seconds
Sleep test, ptosis often resolves after 20-30
minutes in a dark room with the eyelids closed.
Cogan twitch
overshoot
of the eyelid when the patient looks straight ahead after looking down for several
minutes

83. Neostigmine (Prostigmine) test Ice test
Tensilon test
Neostigmine (Prostigmine) test
Ice test
External application of ice for 2-5 minutes improves function of the levator and other
affected extraocular muscles, giving a rapid and reliable method of establishing this diagnosis
without the need for drug administration.

84. Electromyography
shows decreased electrical activity of involved muscles after prolonged voluntary innervation an
increased activity (including saccadic velocity) after the administration of edrophonium or neostigmine.
Documentation of abnormalities in single-fiber electromyography or the presence of circulating antiacetylcholine receptor antibodies is confirmatory
although a negative result does not rule out the presence of
this disease.