Transcript Vertical-Deviations-1390

Vertical Deviations
Abbas Attarzadeh
Professor of ophthalmology
Shiraz University of medical sciences
Vertical deviation (vertical
misalignment of the visual axes)
• Comitant
• Incomitant
The majority of vertical deviations are
incomitant
• Dysfunctional overactions or underactions of
the superior and inferior oblique muscles
• Paralysis (paresis or palsy) of cyclovertical
muscles
• Contracture cyclovertical muscles
• Restriction of vertical movement
• Orbitopathy
A vertical deviation is described according to
the direction of the vertically deviating non
fixating eye.
• If the left eye is higher than the right
and the right eye is fixating,
this is called a left hypertropia
• If the left eye is lower than the right
and the right eye is fixating,
is called a left hypotropia
• If the ability to alternately fixate is present, the deviation is named for
the usually hyperdeviating eye in ordinary visual circumstances (ie, not
during cover testing)
Inferior Oblique Muscle Overaction
• Overaction of the inferior oblique muscle is
termed primary when it is not associated with
superior oblique muscle paralysis.
• It is called secondary when it accompanies
paresis or palsy of its antagonist superior
oblique muscle or yoke inferior rectus muscle.
The cause of primary overaction is not well
understood.
• One explanation involves vestibular influences
governing postural tonus of the extraocular
muscles.
• Some observers have questioned the concept
of a true inferior oblique overaction,
preferring to describe the movement as over
elevation in adduction.
• Magnetic resonance imaging (MRI) studies
have demonstrated a connective tissue pulley
where the inferior oblique muscle's path
crosses that of the inferior rectus muscle, the
latter also having a pulley.
• This arrangement is said to lead to a dynamic
interaction of these structures during vertical
rotation that could give the appearance of
overaction.
Clinical Features
• Primary inferior oblique muscle overact ion has
been reported to develop between ages 1 and 6
years In up to two thirds of patients with
congenital esotropia.
• The entity also occurs, less frequently, in
association with acquired esotropia or exotropia
and occasionally in patients with no other form of
strabismus.
• A bilateral overaction can be asymmetric,
because of either different times of onset or
different degrees of severity.
In adduction, the eye is elevated;
this is apparent with the eyes in lateral gaze
and the abducting eye fixating, as well as with
the eyes in lateral up gaze
• Alternate cover testing under these conditions
shows that the higher eye refixates with a
downward movement and that the lower eye
does so with an upward movement.
• When inferior oblique overaction is bilateral,
the higher and lower eyes reverse in the
opposite lateral gaze.
Differentia Diagnosis with DVD
• Neither eye refixates with an upward
movement whether adducted, abducted, or in
primary position.
• A-V pattern horizontal deviation is common
with overacting inferior oblique muscles but
not with DVD.
Management
• In all but the mildest cases, a weakening procedure on the inferior oblique
muscle
1.
Recession
2.
Disinsertion
3.
Myectomy
4.
Anterior transposition
• Structural variations in this muscle or its path may affect the surgical
result.
• Weakening the inferior oblique muscles has an insignificant effect on
primary position
• horizontal alignment. An associated horizontal deviation requiring surgical
correction is treated at the same operative session.
Anterior transposition
• Anterior transposition is another effective weakening
procedure that can correct marked overaction of the
inferior oblique muscles and DVD, particularly when both
are present simultaneously.
• Excessive excyclotorsion due to the overaction can also be
improved
• by this procedure. Actual results vary according to the new
location of the anterior and posterior fibers of the
reinserted inferior oblique muscle.
• Caution is advisable because excessively anterior and
spread-out reattachment can restrict elevation, especially
when the eye is abducted (anti-elevation syndrome).
Prevetion of Antielevation
1. Cutting IO away from insertion
2. Anteriorization of posterior fibers more than
usual
3. insertions of the inferior oblique muscles
are spread out laterally
J AAPOS. 1997 Mar;1(1):55-62.
Restriction of elevation in abduction after inferior oblique anteriorization.
Kushner BJ.
University of Wisconsin, Department of Ophthalmology and Visual Sciences,
Madison, USA
.
CONCLUSIONS: Anteriorization of the inferior oblique
muscles more than 1 mm anterior to the insertions
of the inferior rectus muscle may cause a limitation
of elevation in abduction, resulting in a Y or V
pattern that mimics inferior oblique overaction.
This may be more likely to occur if the new
insertions of the inferior oblique muscles are spread
out laterally at the time of anteriorization.
SUPERIOR OBLIQUE MUSCLE
OVERACTION
Almost all cases of bilateral superior oblique
muscle overaction can be considered primary,
because paralysis of the inferior rectus and
inferior oblique muscles is uncommon.
Clinical Features
• A vertical deviation occurs with unilateral or
asymmetric bilateral overaction
• The lower eye contains the unilaterally, or more
prominent bilaterally
• An associated horizontal deviation exotropia
• The overacting superior oblique muscle also causes
depression, with resulting hypotropia of the adducting eye
in lateral gaze, which is accentuated in lateral downgaze
• An alternative term for this finding is
overdepression in adduction.
Management
• Clinically significant hyper- or hypotropia
• A pattern,
Bilateral superior oblique tendon-weakening procedure
Recession
Tenotomy
Tenectomy
Lengthening by insertion of:
Silicone expander
Nonabsorbable suture
Or Z-splitting)
SO tenotomy
SR
LR
IO
IO
LR
RM
IR
MR
SR
IR
For those surgeons who are a little
too chicken to completely cut the
SO tendon and cause a SO palsy…
Chicken suture technique
Chicken suture
For those surgeons with a sense of
humor…
Try the rubber chicken trick
aka silicone expander
Silicone expander
•
However, many surgeons are reluctant to
perform superior oblique weakening in
patients with normal stereopsis,
• Horizontal deviation is corrected at the
same operative session.
Some surgeons, Anticipating a convergent
effect, adjust their surgical amounts for
horizontal rectus muscles modestly when
simultaneously weakening the superior
oblique muscles.
DISSOCIATED VERTICAL DEVIATION
Dissociated vertical deviation (DVD)
is a common innervational disorder,
found in 50%-90% of patients with
congenital esotropia and in other
forms of strabismus
cause
• The cause is unknown, but DVD appears to be
associated with early disruption of binocular
development.
• Recent work has suggested that DVD may be
the result of compensating mechanisms for
latent nystagmus, with the oblique muscles
having the principal role.
• DVD usually presents after age 2 years,
• whether or not the horizontal deviation it accompanies
has been surgically corrected.
• Either eye may spontaneously and slowly drift
upward and outward, with simultaneous extorsion
when an eye is occluded or during periods of visual
inattention
• Some patients attempt to compensate by tilting
the head, for reasons that still have not been
conclusively identified.
• As the vertically deviated eye moves down (and
intorts) to fixate when the previously fixating
fellow eye is occluded, the latter makes no
downward movement.
• In contrast, as noted, eyes with DVD have no
corresponding hypotropia of the fellow eye when
the hypertropic eye
refixates. In this respect,
Hering's law of equal innervation appears not
to apply to DVD.
DHD
The vertical movement usually
predominates, but sometimes the principal
dissociated movement is one of abduction
(dissociated horizontal deviation).
DVD
• The condition is usually bilateral although
frequently asymmetric.
DVD
1.
Occur spontaneously (manifest DVD)
2.
when 1 eye is occluded (latent DVD)
• DHD +latent nystagmus and horizontal strabismus
are often associated with DVD
Measurement of DVD
is difficult and imprecise.
1. One method uses base-down prism in front
of the upwardly deviating eye while it is
behind an occluder
2. The occluder is then switched to the fixating
lower eye.
3. The base-down prism power is adjusted until
the deviating eye shows no downward
movement to refixate.
Measurement of DVD
is difficult and imprecise.
•
One method uses base-down prism in front of the upwardly deviating eye while it is behind an occluder
•
The occluder is then switched to the fixating lower eye.
•
The base-down prism power is adjusted until the deviating
•
eye shows no downward movement to refixate.
Results are similar when
1.
2.
3.
4.
A red Maddox rod is used to generate a
horizontal stripe viewed by the dissociated
higher eye
While the other eye fixates on a small light
vertical prism power is used to eliminate the
separation of the light and the line.
Each eye is tested separately in cases of
bilateral DVD.
Another method,
•
using a modified form of the Krimsky test,
•
is particularly useful in evaluating patients who cannot fixate with the deviating eye.
•
•
The deviation can also simplybe graded on a 1+ (least) to 4+ (most) scale.
The earlier discussion of inferior oblique muscle overaction describes the features that distinguish that condition from DVD.
Measurement of DVD
is difficult and imprecise.
•
One method uses base-down prism in front of the upwardly deviating eye while it is behind an occluder
•
The occluder is then switched to the fixating lower eye.
•
The base-down prism power is adjusted until the deviating
•
eye shows no downward movement to refixate.
Results are similar when
•
•
•
•
a red Maddox rod is used to generate a horizontal stripe viewed by the dissociated higher eye
While the other eye fixates on a small light;
vertical prism power is used to eliminate the separation of the light and the line.
Each eye is tested separately in cases of bilateral DVD.
Another method,
• using a modified form of the Krimsky test,
• is particularly useful in evaluating patients
who cannot fixate with the deviating eye.
•
•
The deviation can also simplybe graded on a 1+ (least) to 4+ (most) scale.
The earlier discussion of inferior oblique muscle overaction describes the features that distinguish that condition from DVD.
Management
Treatment for DVD is indicated if:
1. the vertical deviation occurs spontaneously,
2. Is frequent
3. Cosmetically significant
Changing the fixation preference by patching or
by penalization
is effective mostly in unilateral or highly
asymetric bilateral DVD
Surgical treatment
often improves the condition but rarely
eliminates it.
Distinguishing DVD from overaction of the
inferior oblique muscles is important because
the surgical approaches to these 2 conditions
are different in most cases, although inferior
oblique muscle anterior transposition can be
suitable in either entity
Differentia Diagnosis with DVD
• Neither eye refixates with an upward
movement whether adducted, abducted, or in
primary position.
• A-V pattern horizontal deviation is common
with overacting inferior oblique muscles but
not with DVD.
SUPERIOR OBLIQUE MUSCLE
PARALYSIS (PALSY OR PARESIS)
Superior Oblique Palsy
The most common single cyclovertical muscle
paralysis encountered by the ophthalmologist
is the fourth cranial (trochlear) nerve palsy,
involving the superior oblique muscle.
fourth cranial (trochlear) nerve palsy
1. Congenital
2. Acquired
Usually as a result of:
Closed head trauma
Less commonly :
Central nervous system vascular problem
Brain tumors
Diabetes
1.
The same clinical features can result from a
congenitally lax, attenuated, or even absent
superior oblique tendon, a developmental
rather than a neurologic feature,
2. Or from unusual pathways of the muscle
3. Or functional consequences of orbital
pulleys.
Superior oblique muscle
underaction can also occur in
several craniofacial abnormality
DDX congenital from acquired superior
oblique muscle palsy
1. Congenital cases are usually unilateral, and
acquired cases are more often bilateral.
2. Examine old family photographs to detect a
compensatory head tilt extending back to
childhood
3. Facial asymmetry from long-standing head
tilting and
4. Large vertical fusional amplitudes also
indicate chronicity.
DDX congenital from acquired superior
oblique muscle palsy
• The distinction is important because acquired palsies that
cannot be reasonably attributed to known instances of
trauma suggest the possibility of serious intracranial lesions
and the need for often extensive neurologic investigation.
• Markedly asymmetric bilateral palsies that initially appear
to be unilateral have
prompted the term masked bilateral.
• Direct trauma to the tendon or the trochlear area is an
unusual cause of unilateral superior oblique muscle palsy.
Clinical Features
Examination of versions
• Underaction of the involved superior oblique
muscle
• Overaction of its antagonist inferior oblique
muscle
Overaction of its antagonist inferior oblique
muscle
Underaction of the involved superior oblique
muscle
• Double Maddox rod testing to measure torsional
imbalance.
• Indirect ophthalmoscope fundus examination
• 3-step determination
However, 3-step test results can be abnormal in
some cases of :
DVD
Entities involving restriction
and therefore can be misleading.
BE IOOA
Fundus
Xtorsion
correlates
with ‘V’ &
IOOA
Grading of torsion
(LE, inverted view)
LK:
1/3: trace or slight
3/3: huge
2/3: in between
skew deviation
• skew deviation show results on the
3-step test that mimic a superior
oblique muscle palsy.
• Intorsion-instead of the expected
extorsion-determined by double
Maddox rod testing and by
ophthalmoscopy, identifies
such cases, especially when there
are associated neurologic findings.
Left Eye
• Assessment of the ocular
deviation in the diagnostic
gaze positions, as well as with
• right and left head tilt, is
important in diagnosing and
planning treatment for
superior
• oblique muscle palsy
• Some ophthalmologists document serial
changes
• in the deviation by means of the Hess screen
or Lancaster red-green test, or plot the
• field of binocular single vision, to follow
patients with superior oblique muscle palsy
SO palsy
Unilateral cases
Bilateral cases
V pattern
little if any V pattern
usually show a V pattern ,Easotropia in
down gaze
Excyclotorsion
less than 5°
at least 5° and
is highly diagnostic when 10° or more
The 3-step test
The 3-step test yields
positive results for the
involved side only
Bielschowsky head-tilt test yields positive
results on tilt to each side
Ductions
Normal or diminished.
The ductions attributable to
both superior oblique muscles usually
are diminished.
Fixation
Either the normal or
the affected eye can be
preferred for fixation
Either eye can be preferred for fixation
Abnormal head positions
Are common,
Not revealing
usually a head tilt toward
the shoulder opposite the
side of the weakness.
Amblyopia &
excyclotorsion
is uncommon in acquired
palsies but may be
present in congenital
ones.
Signs of bilaterality in cases
initially thought to be unilateral include
bilateral objective fundus excyclotorsion
Management
Indications for treatment are:
1. Abnormal head position
2. Significant vertical deviation
3. Diplopia,
4. Asthenopia
• Surgery is indicated in most cases.
• Prisms may be used to overcome diplopia in
small, symptomatic, nearly comitant deviations
that lack a prominent torsional component.
Unilateral superior oblique paralysis
• The first approach to unilateral superior
oblique paralysis is usually weakening of the
antagonist inferior oblique muscle when it is
overacting and the deviation in primary
position is no greater than 15 ∆.
• It is important to determine that the case is
not one of skew deviation,
(As inferior oblique muscle weakening would
aggravate the incyclotorsion of the higher eye)
If the deviation is greater than 15∆,
one should consider adding a second
muscle to the procedure
• The usually favored choices are recession of the
contralateral (yoke) inferior rectus muscle
• Tucking the tendon of the weak superior oblique muscle if
it is significantly lax.
• The surgical plan should include recession of the ipsilateral
superior rectus muscle if a forced duction test shows
limited depression on the side of the hypertropia.
In cases of So palsies with contracture of the
ipsilateral superior
rectus muscle
• The deficient depression and the deviation in right gaze
are more like those of the deviation in primary position
and left gaze, a so-called spread of comitance.
• On version testing, Hering's law may cause this to
appear to represent superior oblique muscle
overaction in the normal eye.
• If the surgeon is misled and performs superior oblique
tenotomy on the normal eye, thereby converting a
unilateral superior oblique palsy to a bilateral one,
disabling torsional diplopia can result
In the unusually severe case with a vertical
deviation greater than 35∆ in primary position
3-muscle surgery usually is required.
In this situation, most surgeons would favor
Recession of the overacting antagonist inferior
oblique muscle
superior oblique tendon tuck,
and either ipsilateral superior rectus recession or
contralateral inferior rectus
recession, as dictated by forced duction test
results.
Whatever the approach, it is important to
avoid overcorrection of a long-standing
unilateral superior oblique muscle paralysis in
an adult patient:
overcorrection will be aggravated with time
and often causes disabling diplopia resembling
the original problem.
Bilateral superior oblique paralysis
• In the case of bilateral superior oblique
paralysis, surgery is performed on both eyes,
graded for unequal severity if necessary.
• Bilateral inferior oblique muscle weakening is
appropriate but may not be completely
effective.
• Other options, as for unilateral palsy, are
inferior rectus muscle recession,
tucking of the superior oblique
tendon, and the Harada-Ito
procedure
Inferior rectus muscle recession can be
adjusted and is easily graded
Care is required to avoid postoperative
recession of the lower eyelid margin
Surgical treatment
For congenital SO palsy,
– If there is a flappy tendon.Shorten, or
tighten the superior oblique tendon in
comparison to fellow eye
– If the tendon is not flappy consider
ipsilateral IO weekening or contralateral IR
recess
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
SO
LR
RM
IR
IO
IO
Dr. G.Vicente
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
SO
LR
RM
IR
IO
IO
Dr. G.Vicente
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
SO
LR
RM
IR
IO
IO
Dr. G.Vicente
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
MR
LR
IO
IO
LR
RM
IR
SR
SO
IR
Dr. G.Vicente
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
MR
LR
IO
IO
LR
RM
IR
SR
SO
IR
Dr. G.Vicente
Congenital Superior oblique palsy
surgery to shorten floppy tendon
SR
MR
LR
IO
IO
LR
RM
IR
SR
SO
IR
Dr. G.Vicente
Acquired SO palsies
• If vertical deviation<15PD and the IO
overacts,Weaken the opposing muscle,
inferior oblique
If there is no IO overaction,consider
contralateral IR recess
• If vertical deviation is large >15PD, consider
recession of contralateral inferior rectus.
If longstanding and the eye has poor
depression, the superior rectus is likely
contracted and should be recessed.
Acquired Superior oblique palsy
Surgery to improve torsion
and vertical alignment
SR
LR
IO
Recess IR (contralateral)
LR
RM
IR
MR
SR
IR
IO
Recess IO
Dr. G.Vicente
Harada Ito Procedure
• If little vertical deviation but large extorsional
component Consider Harada-Ito procedure:
• Anteriorly displaced anterior half of the SO
tendon and inserted at the superior border of
lateral rectus. Lateralizing the anterior fibers
intorts the eye, while the posterior fibers are
intact
• Tightening the whole tendon would cause a
Brown syndrome.
Harada-Ito
Anterior displacement of ½ SO tendon
Dr. G.Vicente
Harada-Ito
Anterior displacement of ½ SO tendon
Dr. G.Vicente
Harada-Ito
Anterior displacement of ½ SO tendon
Dr. G.Vicente
Because of asymmetry in bilateral superior
oblique palsy, with a prominent vertical
component in one eye and more prominent
excyclotorsion in the fellow eye, Pinchoff and
coworkers have recommended a superior
oblique tuck on the eye with the vertical
component and an adjustable Harada-Ito
procedure on the eye with the prominent
excyclotorsion.
Botox injection:
• Garnham and coworkers studied the effect
of botulinum toxin A, as an alternative to
surgery, in 20 patients with fourth CN palsies.
They concluded that botulinum toxin injection
showed greatest benefit when injecting the
inferior rectus for residual deviations but was of
limited value when injecting the inferior oblique
as the primary therapy in chronic fourth CN
palsy.
TREATMENT MORBIDITY
• Sup Obl
– Brown’s
– Ptosis
• Inf Obl
– Upgaze restriction
– Lid change
INFERIOR OBLIQUE MUSCLE PALSY
• Damage to the inferior division of cranial
nerve III and especially to the branch that
supplies the inferior oblique muscle has been
proposed as the cause of inferior oblique
muscle palsy.
• Consider skew deviation.
• The descriptive term
underelevation in adduction may be
preferable.
Clinical Features
• Elevation is deficient in the adducted position
of the eye.
• Forced ductions are free when the adducted
eye is elevated.
• An A pattern and overact ion of the
ipsilateral superior oblique muscle are
usually present
skew deviation
Even if the diagnosis of inferior oblique muscle palsy is
supported by findings of the 3-step test the same results
have been observed in some cases
thought to represent skew deviation.
In inferior oblique muscle palsy, the hypotropic eye should
be incyclotorted
In skew deviation, the hypotropic eye is seen to be
Excyclotorted
These phenomena are analogous to those described for
superior oblique palsy
Management
Indications for treatment of "true" inferior
oblique muscle palsy are:
1. Abnormal head position
2. Vertical deviation in primary gaze
3. Diplopia
Management consists of either:
• ipsilateral superior oblique muscle weakening
• Or contralateral superior rectus muscle
recession.
• If the former procedure aggravate the
excyclotorsion of the hypotropic eye that is
already present if skew deviation is the
underlying cause
Comparison of Inferior Oblique Muscle
Palsy With Brown Syndrome
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
MONOCULAR ELEVATION
DEFICIENCY
Monocular Elevation Deficiency
(Double Elevator Palsy)
strabismus manifesting deficient elevation in
all horizontal orientations of the eye
• inferior rectus muscle restriction
• weakness of one or both elevator muscles
Clinical Features
Three types of monocular elevation deficiency are found:
• 1. with inferior rectus restriction .positive forced duction for
elevation .normal elevation force generation and elevation saccadic
velocity (no muscle paralysis) .often an extra or deeper lower eyelid
fold on the affected side .poor or absent Bell's phenomenon
• 2. with elevator weakness .free forced ductions .reduced elevation
force generation and saccadic velocity .Bell's phenomenon often
preserved (indicating a supranuclear cause)
• 3. combination (inferior rectus restriction and weak muscles of
elevation) .positive forced duction for elevation .reduced force
generation and saccadic velocity for elevation
Management
• Indications for treatment include:
• A large vertical deviation in primary position,
with or without ptosis
• Abnormal head position, usually chin-up.
• If inferior rectus muscle restriction is present, this
muscle should be recessed.
• If there is no restriction, the medial rectus and
the lateral rectus muscles should be transposed
toward the superior rectus
muscle (Knapp procedure).
Upper eyelid surgery for ptosis should be deferred
until after the vertical deviation has been
corrected.
Blow out fracture
Orbital Floor Fractures
• Blunt facial trauma is the usual cause of
orbital floor fractures; auto accidents account
for most of these.
• The injury is considered to be caused by an
acute increase in intraorbital pressure from a
direct impact that closes the orbital entrance,
with or without injury to its rim.
• In the latter instance, this is termed blowout
fracture.
• Fracture of the orbital floor can be part of more
extensive fractures of the midface, including the
orbital rim or the zygomatic complex.
• Damage to the inferior rectus muscle with
resulting weakness may be caused by
hemorrhage or ischemia from direct trauma to
the muscle or injury to its nerve; it can occur
either at the time of injury or at the time the
orbital floor fracture is repaired.
Orbital Floor Fractures
• It is clear that as soon as appropriate
indications for surgery are confirmed, it is
appropriate to proceed.
• Early surgery is technically easier before soft
tissue scarring and bony malunion progress.
In cases with obvious clinical and CT evidence
of frank muscle entrapment, expeditious
repair is advised (within 48 hours if possible)
to minimize ischemic muscle injury and
fibrosis, which may otherwise limit final
outcome .
• Forced duction and force-generation testing may be
performed during this time to assess the etiology
and severity of strabismus.
• However, the previously mentioned caveat holds:
forced duction testing may be positive after the
initial injury as a result of edema or hemorrhage,
thus limiting the utility of this test early on.
• In this subset of patients, ocular motility is assessed
more reliably after the orbital edema subsides .
Surgery
Mild Ahmady
• Based on review of the literature, it is reasonable to tell the
patient that diplopia will typically stay the same or improve
with time,
• whereas enophthalmos will stay the same or worsen with
time (i.e 3 ,.to 6 months).
• Although secondary orbital, eyelid, or strabismus surgery
can be performed many months after the initial injury
• there is widespread agreement that the results of
such surgery are not as successful as primary orbital
fracture repair
4 days post surgery
Diplopia
• After blow-out fracture repair may be due to persistent
orbital soft tissue entrapment,
• But it may also be due to coincident extraocular muscle
injury or neurologic injury.
• Postoperative orbital edema may also be associated with
generalized limitation of ocular motility; therefore, ocular
motility is most appropriately reassessed after the edema
resolves (usually in 2 to 3 weeks).
• Repeat CT scanning may also be helpful. If the clinical
examination and CT findings are suggestive of persistent
extraocular muscle entrapment in a patient with functionally
significant diplopia, then early orbital re-exploration is
indicated .
POST SURGERY
• Persistent ocular motility deficits that are not amenable to orbital
surgery generally require strabismus surgery.
• Usually a period of 6 months or more is allowed for spontaneous
improvement, during which time serial orthoptic measurements are
taken.
• Within this waiting period, diplopia may be symptomatically treated
with Fresnel prisms, fogging (partial occlusion), or patching (complete
occlusion) of one eye.
• Young children at risk for amblyopia require closer follow-up and
appropriate treatment should amblyopia develop.
• Most authorities consider blow-out fracture repair successful if diplopia
is relieved within the functional (30°) fields of gaze.
• Reoperation is usually not indicated for diplopia occurring in more
eccentric fields of gaze, although each case must be individualized.
Damage to the inferior rectus muscle with
resulting weakness may be caused by
direct trauma to the muscle or its nerve and
can occur either at the time of injury or at the
time of the repair of an orbital floor fracture.
• Inferior rectus muscle paralysis without prior trauma
is a rare but recognized occurrence.
• If inferior rectus muscle paresis is present without
entrapment, a hypertropia is usually seen in primary
position.
• If paresis is present with entrapment, the patient
may have very little deviation or even a slight
hypotropia in primary position, which decreases in
downgaze
• If entrapment is present, exploration of the fracture
and release of the inferior rectus
• muscle and surrounding tissues may limit the
subsequent damage. The initial management
• of inferior rectus muscle paresis without entrapment
is observation because the
• paresis may reverse with time. If recovery does not
take place within 6 months of the
• injury, muscle surgery may be indicated.
• Residual strabismus generally can be
corrected using standard eye muscle surgical
techniques.
• For partial inferior rectus muscle paresis, a
resection of the affected muscle combined
with a recession of the ipsilateral superior
rectus muscle can be performed.
Alternatively, a recession of the contralateral
inferior rectus muscle with or without the
addition of a posterior fixation suture can be
used to limit downgaze and match the duction
deficiency of the injured eye.
• Residual strabismus generally can be corrected using standard
eye muscle surgical techniques.
• For partial inferior rectus muscle paresis, a resection of the
affected muscle combined with a recession of the ipsilateral
superior rectus muscle can be performed.
• Alternatively, a recession of the contralateral inferior rectus
muscle with or without the addition of a posterior fixation
suture can be used to limit downgaze and match the duction
deficiency of the injured eye.
• This approach is particularly useful when diplopia occurs in
the reading position but no deviation is present in primary
position
Transposition of the ipsilateral medial and
lateral rectus muscles to the inferior rectus
muscle (inverse Knapp procedure) can be
performed for complete inferior rectus muscle
paralysis.
• In the presence of limited elevation or depression, a
positive forced duction test
• indicates the presence of restriction. Saccadic velocity and
force generation testing help
• determine whether the eye is further limited in movement
because of a paralytic process.
• Orbital CT and MRI studies of the involved soft tissues are
useful to indicate the extent of
• the fracture and the degree of damage. In some cases,
bradycardia, heart block, nausea, or
• syncope occurs as a vagal response to entrapment. A
complete eye examination should be
• done to detect associated ocular injury.
Surgical management of orbital floor
fractures is controversial
Some clinicians advocate immediate exploration
once the diagnosis is made, irrespective of forced
duction test results.
• Others recommend waiting, from a few days to 2
weeks, for orbital edema and hematoma to
subside
• A few ophthalmologists do not attempt repair of
the fracture and deal only with any subsequent
strabismus.
• .
Abbasy Mahtab
Left Hypotropia & pseudoptosis