Transcript Special Forms of Strabismus

Special Forms of Strabismus
Abbas Attarzadeh MD
Professor of ophthalmology
SUMS
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.
• Most cases of Duane syndrome are sporadic
• 5%-10% show autosomal dominant
inheritance
• A higher prevalence in females
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
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
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.
Clinical Features
1. Poor abduction, frequently with primary
position esotropia 50%-80% in several series
2. Poor adduction and exotropia
3. Poor abduction and adduction, with
esotropia, exotropia, or no primary position
deviation
About 15% of cases are bilateral;
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
Management
Indications for surgery
1. Primary position deviations
2. Abnormal head position
3. Marked globe retraction
4. Large upshoots or downshoots
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
Bimedial Rectus Recess
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
Surgery
The value of botulinum injection into the
medial rectus muscle to improve abduction is
controversial
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
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
LLR recess 13 mm + Bifurcation
LMR Bifurcation
BROWN SYNDROME
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. abandoned this theory
• Restriction of the superior oblique tendon at
the trochlear pulley
Brown Syndrome
Restriction of the superior oblique tendon at
the trochlear pulley
Brown syndrome
bilateral in approximately 10% of cases
• Congenital
Resolution of congenital Brown syndrome is
unusual but possible
• Acquired form
Trauma in the region of the trochlea
Systemic inflammatory
intermittent Brown syndrome, which may
resolve
spontaneously.
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.
Brown syndrome OS
Divergence in upgaze
Down shoot in attempted elevation in adduction?
Down shoot in attempted elev. in adduct. (different than IO palsy)
Brown syndrome
mild
moderate
severe
hypotropia
in primary position
no
no
yes
downshoot of the
eye in adduction.
no
yes
yes
chin-up head posture and sometimes by a face
turnaway
from the affected eye insever cases
• 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.
Management
• Observation alone in about two thirds of all
Brown syndrome cases
• rheumatoid arthritis or other systemic
inflammatory diseases
1. Systemic treatment
2. Corticosteroids injected near the trochlea
• Sinusitis has also led to Brown syndrome
CT of the orbits and paranasal sinuses
Surgical treatment is indicated for the
most severe cases
• Primary position hypotropia
• Anomalous head posture
sheathectomy
has been abandoned in favor of ipsilateral superior oblique tenotomy
• Iatrogenic superior oblique muscle palsy may
occur postoperatively. 44%-82%
Brown Syndrome
SO tenotomy
SR
LR
IO
IO
LR
RM
IR
MR
SR
IR
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
• 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
For those surgeons who are a little
too chicken to completely cut the
SO tendon and cause a SO palsy…
Chicken suture technique
Brown Syndrome
Chicken suture
For those surgeons with a sense of
humor…
Try the rubber chicken trick
aka silicone expander
Brown Syndrome
Silicone expander
Facia Lata
THIRD CRANIAL (OCULOMOTOR)
NERVE PALSY
Traumatic 3rd N palsy
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
Diabetic third cranial nerve palsy generally
• Trauma
resolves spontaneously within 3-4 months.
The majority of adults referred for surgical
• Infection
treatment have palsy due to trauma
• Rarely, tumor
Clinical Features
Limited:
• Adduction
• Elevation
• Depression
• Exotropia and often Hypotropia
• Upper lid ptosis usually is present, often with
a pseudoptosis
ABERRANT REGENERATION
(MISDIRECTION)
Niknam Farshad 23 yo accident 4years ago 3rd nerve palsy aberrant regeneration
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,
Cured III N palsy
• 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.
Sadravy Bahareh post surgery rt 3rd N palsy 15 years po 9.3.86
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
SIXTH CRANIAL (ABDUCENS) NERVE
PALSY
Sixth nerve palsy.ppt
GRAVES EYE DISEASE
motility disturbances
• 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.
Detection of this muscle enlargement by
orbital ultrasound, CT, or MRI helps confirm the
diagnosis of Graves eye disease.
• 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.
Clinical Features
• Severe restrictive, The muscles affected, in decreasing
order of severity and frequency:
1. inferior rectus
2. medial rectus
3. Superior rectus
4. lateral rectus
• The condition most often is bilateral and asymmetric.
• Forced duction test results are almost always positive
in 1 or more directions.
• 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
Management
Indications for strabismus surgery:
1.
Diplopia
2.
Abnormal head position
Surgery may eliminate diplopia in primary gaze
but rarely restores normal motility
• 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
• 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.
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
• 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
Which patients require surgery?
Emergent basis
optic nerve compression
corneal exposure
Non emergent
severe disfiguring proptosis
double vision from restrictive myopathy
eyelid retraction
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
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
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
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
• 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.
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
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
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
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
Chronic Progressive External Ophthalmoplegia
CHRONIC PROGRESSIVE EXTERNAL
OPHTHALMOPLEGIA
Clinical Features
Chronic progressive external ophthalmoplegia
(CPEO) usually begins in childhood
with:
• Ptosis
• Slowly progresses to total paralysis of the
eyelids and extraocular muscles
• CPEO may be sporadic or familial.
• Although a true pigmentary retinal dystrophy
usually is absent, constricted fields and electro
diagnostic abnormalities can occur.
• Defects in mitochondrial DNA have been
found in some patients.
• The triad of :
1. Retinal pigmentary changes
2. CPEO
3. Cardiomyopathy (especially heart block)
is called Kearns-Sayre syndrome
Management
Treatment options are limited.
Cautious surgical elevation (suspension) of the
upper eyelids indicated to lessen a severe
chin-up head position.
MYASTHENIA GRAVIS
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.
• The disease may be purely ocular
• (30%-50%) occurs as part of a major systemic
disorder
• Childhood myasthenia gravis is more common
in females.
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.
• 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
• 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.
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.