11 - Vertical Deviations

Question 1

By convention, vertical deviations are named according to the hypertropic or the hypotropic eye?

Answer 1

By convention, vertical deviations are named according to the hypertropic eye.

Question 2

V ou F : Many vertical deviations are characterized by a hypertropia that is much greater on gaze to one side.

Answer 2

Vrai.
* Many vertical deviations are characterized by a hypertropia that is much greater on gaze to one side.
* They are often, but not exclusively, associated with oblique muscle abnormalities.

Question 3

(Overelevation and Overdepression in Adduction)

Causes of Overelevation in Adduction

Answer 3

Question 4

(Overelevation and Overdepression in Adduction)

Causes of Overdepression in Adduction

Answer 4

Question 5

(Overelevation and Overdepression in Adduction)

Définir oblique muscle pseudo- overactions?

Answer 5

• These include true overaction and underaction of the oblique muscles, as well as several conditions that can simulate oblique muscle overactions.
• These cases have also been termed oblique muscle pseudo- overactions.

Question 6

(Overelevation and Overdepression in Adduction)

Est-il possible d’avoir overaction des m. obliques supérieur et inférieur simultanément? Si oui, donnez des exemples.

Answer 6

Oui.
In some patients, such as those with large- angle exotropia or thyroid eye disease, clinical examination of versions appears to show overaction of both the superior and the inferior oblique muscles.

Question 7

(Inferior oblique muscle overaction)

Overaction of the inferior oblique muscle cause : ODAd ou OEAd?

Answer 7

Overaction of the inferior oblique muscle is one cause of OEAd.

Question 8

(Inferior oblique muscle overaction)

Définir overaction primaire versus secondaire?

Answer 8

• The overaction is termed primary when it is not associated with superior oblique muscle palsy.
• It is called secondary when it accompanies palsy of the superior oblique muscle or the contralateral superior rectus muscle.

Question 9

(Inferior oblique muscle overaction)

Inferior oblique muscle overaction à l’E/O?

Answer 9

The eye is elevated in adduction, both on horizontal movement and in upgaze.

Question 10

(Inferior oblique muscle overaction)

Onset d’un inferior oblique muscle overaction? En association avec quel strabisme?

Answer 10

Primary inferior oblique muscle overaction has been reported to develop between ages 1 and 6 years in up to **two- thirds of patients with infantile strabismus (esotropia or exotropia). **

Question 11

(Inferior oblique muscle overaction)

Est- ce que l’inferior oblique muscle overaction peut aussi survenir dans un contexte d’ésotropie ou exotropie acquise?

Answer 11

Oui.
It also occurs,** less frequently**, in association with acquired esotropia or exotropia and, occasionally, in patients with no other strabismus.

Question 12

(Inferior oblique muscle overaction)

Commentez la symétrie d’un bilateral overaction inferior oblique muscle?

Answer 12

Habituellement symétrique.
Bilateral overaction can be asymmetric, often in patients with poor vision in 1 eye, which leads to greater overaction in that eye.

Question 13

(Inferior oblique muscle overaction)

Commentez le alternate cover testing en lateral gaze lorsque inferior oblique muscle overaction is bilateral.

Answer 13

• With the eyes in lateral gaze, alternate cover testing shows that the higher (adducting) eye refixates with a downward movement and that the lower (abducting) eye refixates with an upward movement.
• When inferior oblique muscle overaction is bilateral, the higher and lower eyes reverse their direction of movement in the opposite lateral gaze.
• These features differentiate inferior oblique overaction from DVD, in which neither eye refixates with an upward movement, whether adducted, abducted, or in primary position.

Question 14

(Inferior oblique muscle overaction)

Type de pattern strabismus objectivable avec un inferior oblique muscle overaction

Answer 14

A V- pattern horizontal deviation and extorsion are common with overacting inferior oblique muscles.

Question 15

(Inferior oblique muscle overaction)

Indicationsto weaken the inferior oblique muscle? What options do we have for this procedure ?

Answer 15

For cases in which inferior oblique overaction produces a functional problem— V-pattern strabismus, hypertropia in primary position, or symptomatic hypertropia in side gaze— a procedure to weaken the inferior oblique muscle (recession, disinsertion, myectomy, or anterior transposition) is indicated.

Question 16

(Inferior oblique muscle overaction)

Exemples de procédures pour weaken the inferior oblique muscle?

Answer 16

Procedure to weaken the inferior oblique muscle
* Recession
* Disinsertion
* Myectomy
* Anterior transposition

Question 17

(Inferior oblique muscle overaction)

V ou F : Weakening of the inferior oblique muscles generally has a significant effect on horizontal alignment in primary position.

Answer 17

Faux.
Weakening of the inferior oblique muscles generally has an insignificant effect on horizontal alignment in primary position.

Question 18

(Superior oblique muscle overaction)

Overaction of the superior oblique muscle cause : ODAd ou OEAd?

Answer 18

Superior oblique muscle overaction is one of several causes of ODAd.

Question 19

(Superior oblique muscle overaction)

Superior oblique muscle overaction à l’E/O?

Answer 19

The overacting superior oblique muscle causes a hypotropia of the adducting eye, which is accentuated in the lower field of gaze.

Question 20

(Superior oblique muscle overaction)

Horizontal deviation associée à un superior oblique muscle overaction?

Answer 20

A horizontal deviation, most often exotropia, may be present and may lead to an A pattern.

Question 21

(Superior oblique muscle overaction)

En plus d’une hypotropie et parfois exotropie, autre déviation associée au superior oblique muscle overaction?

Answer 21

Intorsion is common with superior oblique muscle over action.

Question 22

(Superior oblique muscle overaction)

V ou F : Most cases of bilateral superior oblique overaction are secondary overactions.

Answer 22

Faux. Most cases of bilateral superior oblique overaction are primary overactions.

Question 23

(Superior oblique muscle overaction)

Indications de Tx chirurgical?

Answer 23

In a patient with clinically significant hypertropia or hypotropia or an A pattern, a procedure to weaken the superior oblique tendon (recession, tenotomy, tenectomy, or lengthening by insertion of a silicone spacer or nonabsorbable suture or by split- tendon lengthening) is appropriate.

Question 24

(Superior oblique muscle overaction)

Cible de l’intervention chirurgicale?

Answer 24

In a patient with clinically significant hypertropia or hypotropia or an A pattern, a procedure to weaken the superior oblique tendon (recession, tenotomy, tenectomy, or lengthening by insertion of a silicone spacer or nonabsorbable suture or by split- tendon lengthening) is appropriate.

Question 25

(Superior oblique muscle overaction)

Techniques pour weaken un superior oblique tendon?

Answer 25

Weaken the superior oblique tendon :
* Recession
* Tenotomy
* Tenectomy
* Lengthening by insertion of a silicone spacer or nonabsorbable suture or by split- tendon lengthening

Question 26

(Superior oblique muscle overaction)

Est-ce qu’un chirurgie sur l’oblique supérieur va diminuer l’intorsion (si présente)?

Answer 26

Oui. Significant intorsion will also be reduced with any of these procedures.

Question 27

Most common paralysis of a single cyclovertical muscle

Answer 27

The most common paralysis of a single cyclovertical muscle is fourth nerve (trochlear) palsy, which involves the superior oblique muscle.

Question 28

(Superior Oblique Muscle Palsy)

Causes de Superior Oblique Muscle Palsy?

Answer 28

The palsy can be congenital or acquired; if the latter, it is usually a result of closed head trauma or, less commonly, vascular problems of the central nervous system, diabetes mellitus, or a brain tumor.

Direct trauma to the tendon or the trochlear area is an occasional cause of unilateral superior oblique muscle palsy.

Question 29

(Superior Oblique Muscle Palsy)

Physiopathologie d’un congenital superior oblique muscle palsy?

Answer 29

Results of one study showed that most patients with congenital superior oblique palsy had an absent ipsilateral trochlear nerve and varying degrees of superior oblique muscle hypoplasia.

Question 30

(Superior Oblique Muscle Palsy)

V ou F : Superior oblique muscle underaction can also occur in several craniofacial abnormalities.

Answer 30

Vrai. Superior oblique muscle underaction can also occur in several craniofacial abnormalities.

Question 31

(Superior Oblique Muscle Palsy)

Comment différencier un congenital from acquired superior oblique muscle palsy?

Answer 31

To differentiate congenital from acquired superior oblique muscle palsy :
* The clinician can examine childhood photo graphs of the patient for a preexisting compensatory head tilt, although manifestations of congenital palsy sometimes become apparent only later in life.
* The presence of a large vertical fusional amplitude supports a diagnosis of congenital superior oblique palsy, whereas associated neurologic disorders suggest an acquired condition.
* Facial asymmetry from long- standing head tilting indicates chronicity.

Question 32

(Superior Oblique Muscle Palsy)

Pertinence de la neuroimagerie dans un superior oblique muscle palsy?

Answer 32

Diagnostic evaluation, including neuroimaging, often fails to identify an etiology but may still be warranted for acquired superior oblique palsy without a history of trauma.

Question 33

(Superior Oblique Muscle Palsy)

Préférence de fixation?

Answer 33

Either the normal or the affected eye can be preferred for fixation.

Question 34

(Superior Oblique Muscle Palsy)

Trouvailles à l’E/O des versions?

Answer 34

Examination of versions usually reveals
* Underaction of the involved superior oblique muscle
* Overaction of its antagonist inferior oblique muscle

/!\ The action of the superior oblique muscle can appear normal.

Question 35

(Unilateral Superior Oblique Palsy)

Incomitant ou Comitant?

Answer 35

• In a unilateral palsy, the hyperdeviation is typically incomitant, especially in the acute stages.
• Over time, contracture of the ipsilateral superior rectus or contralateral inferior rectus muscle can lead to “spread of comitance,” with the result that there is minimal difference in the magnitude of the hypertropia when the patient looks from one side to the other.

Question 36

(Unilateral Superior Oblique Palsy)

Comment évaluer un Unilateral Superior Oblique Palsy en présence d’un NC3 palsy (aka depression cannot be evaluted 2nd inability to adduct)?

Answer 36

If depression cannot be evaluated because of the eye’s inability to adduct (ex. in third nerve palsy), superior oblique muscle function can be evaluated by observing whether the eye intorts, as judged by the movement of surface landmarks or examination of the fundus, when the patient attempts to look downward and inward from primary position.

Question 37

(Unilateral Superior Oblique Palsy)

Intorsien ou Extorsion?

Answer 37

• Weakness of the superior oblique muscle also results in extorsion of the eye.
• If the degree of extorsion is large enough, subjective incyclodiplopia, in which the patient describes the image as appearing to tilt inward, can occur.

Action de l’oblique supérieur : dépression, intorsion et abduction

Donc weakness : élévation, extorsion et adduction

Question 38

(Unilateral Superior Oblique Palsy)

Tests pertinents à l’E/O pour Dx un Unilateral Superior Oblique Palsy?

Answer 38

• The diagnosis of unilateral superior oblique muscle palsy is further established by results of the 3- step test and the double Maddox rod test to measure torsion.
• However, results of the 3- step test can be confounded in patients with DVD, entities involving restriction, additional paretic muscles, previous strabismus surgery, or skew deviation.
• Intorsion of the higher eye on fundus examination— instead of the expected extorsion— suggests skew deviation, especially when there are associated neurologic findings.
• In addition, if the patient is placed in a supine position, the vertical tropia is more likely to decrease with skew deviation than with superior oblique palsy.

Question 39

(Unilateral Superior Oblique Palsy)

Définir l’inhibitional palsy of the contralateral antagonist?

Answer 39

• Patients who fixate with the paretic eye can exhibit so- called inhibitional palsy of the contralateral antagonist.
• If a patient with right superior oblique palsy uses the right eye to fixate on an object that is located up and to the left, the innervation of the right inferior oblique muscle required to move the eye into this gaze position is reduced because the right inferior oblique muscle does not have to overcome the normal antagonistic effect of the right superior oblique muscle (Sherrington’s law).
• According to Hering’s law, less innervation is also received by the yoke muscle of the right inferior oblique muscle, which is the left superior rectus muscle.
• This decreased innervation can lead to the impression that the left superior rectus muscle is paretic.

Question 40

(Bilateral Superior Oblique Palsy)

Étiologies plus fréquentes d’un Bilateral Superior Oblique Palsy?

Answer 40

Bilateral superior oblique palsy occurs commonly after head trauma but is sometimes congenital.

Question 41

(Superior Oblique Palsy)

Comment différencier un Unilateral versus un Bilateral Superior OBlique Palsy (ex. V pattern, extorsion, head posistions, hypertropie en primary position, etc.) ?

Answer 41

Unilateral Superior Oblique Palsy :
* Shows little if any V pattern and less than 10° of extorsion in downgaze.
* Subjective incyclodiplopia is uncommon.
* The Bielschowsky head-tilt test (step 3 of the 3- step test) yields positive results for the involved side only.
* Abnormal head positions— usually a tilt toward the shoulder opposite the side of the weakness— are common.
* The oblique muscle dysfunction is confined to the involved eye.

Bilateral Superior Oblique Palsy :
* Usually show a V pattern.
* Extorsion is 10° or more in downgaze; more than 15° of extorsion in primary position is highly suggestive of bilateral involvement.
* Subjective incyclodiplopia is common in acquired bilateral cases.
* The Bielschowsky head- tilt test yields positive results on tilt to each side— that is, right head tilt produces a right hypertropia and left head tilt, a left hypertropia.
* There is bilateral oblique muscle dysfunction.
* Patients may exhibit a chin- down head position.
* Symmetric palsies may show little or no hypertropia in primary position.

Question 42

(Superior Oblique Palsy)

Définir le Masked Bilateral Superior Oblique Palsy?

Answer 42

Markedly asymmetric bilateral superior oblique palsy that initially appears to be unilateral is called masked bilateral palsy.

Question 43

(Masked Bilateral Superior Oblique Palsy)

Signs of masked bilateral palsy

Answer 43

Signs of masked bilateral palsy include
* Bilateral objective fundus extorsion
* Esotropia in downgaze
* Even the mildest degree of oblique muscle dysfunction on the presumably uninvolved side

Question 44

(Masked Bilateral Superior Oblique Palsy)

Common cause

Answer 44

Masked bilateral palsy is more common in patients with head trauma.

Question 45

(Superior Oblique Palsy)

Indications de chx?

Answer 45

Indications for surgery :
* Abnormal head position
* Significant vertical deviation
* Diplopia
* Asthenopia

Question 46

(Superior Oblique Palsy)

Indication pour une prescription de prismes?

Answer 46

For small, symptomatic deviations that lack a prominent torsional component — especially those that have become comitant— prisms that compensate for the hyperdeviation in primary position may be used to overcome diplopia.

Question 47

(Unilateral Superior Oblique Muscle Palsy)

Tx chirurgical

Answer 47

Question 48

(Bilateral Superior Oblique Muscle Palsy)

Tx chirurgical d’une parésie asymétrique?

Answer 48

If the paresis is asymmetric, hypertropia in primary position may be present and require many of the same considerations as hypertropia in unilateral palsy.

Question 49

(Bilateral Superior Oblique Muscle Palsy)

Tx chirurgical d’une parésie symmétrique (minimal hypertropia in primary position)?

Answer 49

If the palsies are symmetric (minimal hypertropia in primary position), both inferior oblique muscles can be weakened if they are overacting and hypertropia is present in side gaze.
Bilateral superior oblique muscle tightening should be performed when hypertropia in side gaze is accompanied by V-pattern esotropia or symptomatic extorsion, especially in downgaze.

Question 50

(Inferior Oblique Muscle Palsy)

Étiologies d’un inferior oblique muscle palsy?

Answer 50

Most cases are considered to be congenital or posttraumatic.

Question 51

(Inferior Oblique Muscle Palsy)

Caractéristiques à l’E/O d’un Inferior Oblique Muscle Palsy?

Answer 51

Inferior oblique palsy is suspected when the patient has hypotropia and 3- step- test results consistent with this diagnosis.
Prominent feature is deficient elevation when the eye is in adduction.

Question 52

(Inferior Oblique Muscle Palsy)

Inferior Oblique Muscle Palsy versus Brown Syndrome?

Answer 52

Question 53

(Inferior Oblique Muscle Palsy)

Indications et Tx chirurgical d’un Inferior Oblique Muscle Palsy

Answer 53

• Indications for treatment of inferior oblique muscle palsy are abnormal head position, vertical deviation in primary position, and diplopia.
• Management consists of weakening either the ipsilateral superior oblique muscle or the contralateral superior rectus muscle.

Question 54

(Skew deviation)

Définir le skew deviation

Answer 54

• Skew deviation is an acquired vertical strabismus that can mimic superior or inferior oblique palsy.
• The deviation is due to **peripheral or central asymmetric disruption of supranuclear input from the otolith organs. **

Question 55

Comment distinguer un Skew deviation d’un superior ou inferior oblique palsy?

Answer 55

• Intorsion of the hypertropic eye on fundus examination— rather than the expected extorsion in superior oblique palsy— suggests skew deviation, particularly when there are associated neurologic findings.
• In addition, if the patient is placed in a supine position, the vertical tropia is more likely to decrease with skew deviation than with superior oblique palsy.
• Similarly, if there is extorsion of the hypotropic eye on fundus examination— instead of the expected intorsion in inferior oblique palsy— then skew deviation is the likely diagnosis.

Question 56

(Monocular Elevation Deficiency)

Définir le Monocular elevation deficiency?

Answer 56

Monocular elevation deficiency (previously termed double- elevator palsy) involves a limitation of upward gaze with a hypotropia that is similar in adduction and abduction.

Question 57

(Monocular Elevation Deficiency)

3 forms of this motility pattern

Answer 57

There are 3 forms of this motility pattern, each with a different cause:
* Restriction of the inferior rectus muscle;
* Deficient innervation of elevator muscles (paresis of 1 or both elevator muscles or a monocular supranuclear gaze disorder);
* Combination of restriction and elevator muscle deficit.

Question 58

(Monocular Elevation Deficiency)

Caractéristiques communes des 3 formes d’atteinte

Answer 58

All 3 forms of monocular elevation deficiency are characterized by
* Hypotropia of the involved eye with limited elevation
* A chin-up head position with binocular fusion in downgaze
* Ptosis or pseudoptosis

Question 59

(Monocular Elevation Deficiency)

% de patients avec une vraie ptose? À quelle étiologie doit-on penser dans un contexte de monocular elevation defiency?

Answer 59

• True ptosis is present in 50% of affected patients.
• These are features of third nerve palsy, as well.
• Therefore, if any other feature of third nerve palsy is present, that condition should be suspected rather than monocular elevation deficiency.

Question 60

(Monocular Elevation Deficiency)

Clinical features of monocular elevation deficiency 2nd restriction (forced duction, force generation, saccadic velocity, etc.)?

Answer 60

Restriction
* Positive forced duction on elevation
* Normal force generation and saccadic velocity (no muscle paralysis)
* Often an extra or deeper lower eyelid fold on attempted upgaze
* Poor or absent Bell phenomenon

Question 61

(Monocular Elevation Deficiency)

Clinical features of monocular elevation deficiency 2nd elevator muscle innervational deficit (forced duction, force generation, saccadic velocity, etc.)?

Answer 61

Elevator muscle innervational deficit
* Negative forced duction on elevation
* Reduced force generation and saccadic velocity
* Preservation of Bell phenomenon (indicating a supranuclear cause) in many cases
* Combination of restriction and elevator muscle deficit

Question 62

(Monocular Elevation Deficiency)

Clinical features of monocular elevation deficiency 2nd restriction (forced duction, force generation, saccadic velocity, etc.)?

Answer 62

Positive forced duction on elevation
* Reduced force generation and saccadic velocity

Question 63

(Monocular Elevation Deficiency)

Indications de Tx

Answer 63

Indications for treatment include
* A large vertical deviation in primary position, with or without ptosis
* An abnormal chin-up head position.

Question 64

(Monocular Elevation Deficiency)

Techniques chirurgicales indiquées pour un Monocular Elevation Deficiency?

Answer 64

• If restriction originating inferiorly is present, the inferior rectus muscle should be recessed.
• If there is no restriction, the medial and lateral rectus muscles can be transposed toward the superior rectus muscle (Knapp procedure).
• Alternatively, the surgeon can recess the ipsilateral inferior rectus and either recess the contralateral superior rectus muscle or resect the ipsilateral superior rectus muscle.
• Ptosis surgery should be deferred until the vertical deviation has been corrected and the pseudoptosis component eliminated.

Question 65

(Monocular Elevation Deficiency)

Faut-il corriger l’Hypertropie ou la Ptose en premier?

Answer 65

Ptosis surgery should be deferred until the vertical deviation has been corrected and the pseudoptosis component eliminated.

Question 66

(Orbital Floor Fractures)

V ou F : la présence de diplopie en post-injury immédiat est une indication d’intervention chirurgicale urgente.

Answer 66

Faux. Diplopia in the immediate postinjury stage is common and not necessarily an indication for urgent intervention.

Question 67

(Orbital Floor Fractures)

Causes de la diplopie en post-injury?

Answer 67

Depending on the site of the bony trauma, muscles can be either
* Restricted due to entrapment
* Paretic due to muscle contusion or nerve damage

« Flap tears » of the inferior rectus muscle have also been described by some authors as a cause of limitation of elevation, depression, or both.

Paresis of a muscle may resolve over several months.

If the fracture requires surgery, the range of eye movements may improve.

By contrast, fibrosis after trauma may cause restriction to persist even after successful repair of the fracture.

Question 68

(Orbital Floor Fractures)

Indications de Tx du strabisme?

Answer 68

Treatment of strabismus is usually necessary when diplopia persists in primary position or downgaze or there is an associated compensatory head position.

Question 69

(Orbital Floor Fractures)

Tx de mild limitations of eye mvts?

Answer 69

Some mild limitations of eye movements can be managed with prisms.

Question 70

(Dissociated vertical deviation)

Qu’est-ce que le DVD?

Answer 70

Dissociated vertical deviation (DVD) is an innervational disorder found in more than 50% of patients with infantile strabismus (esotropia or exotropia).

Question 71

(Dissociated vertical deviation)

% de patients avec strabisme infantile qui présente aussi un DVD?

Answer 71

Dissociated vertical deviation (DVD) is an innervational disorder found in more than 50% of patients with infantile strabismus (esotropia or exotropia).

Question 72

(Dissociated vertical deviation)

Physiopathologie/Explication de l’origine du DVD?

Answer 72

• There are 2 explanations for the origin of DVD.
• One theory is that DVD is a vertical vergence movement to damp latent nystagmus, with the oblique muscles playing the principal role.
• An alternative theory suggests that deficient fusion allows the primitive dorsal light reflex, which is prominent in other species, to emerge.

Question 73

(Dissociated vertical deviation)

Onset of DVD généralement?

Answer 73

Dissociated vertical deviation usually presents by age 2 years, whether or not any horizontal deviation has been surgically corrected.

Question 74

(Dissociated vertical deviation)

Clinical features d’un DVD à l’E/O?

Answer 74

• Either eye slowly drifts upward and outward, with simultaneous extorsion, when occluded or during periods of visual inattention (Fig 11-8).
• Some patients attempt to compensate by tilting the head, for reasons that still have not been conclusively identified.

In addition to DHD, latent nystagmus and horizontal strabismus are often associated with DVD.
* These entities are manifestations of deficient binocular vision.

Question 75

(Dissociated vertical deviation)

Dans un dissociated strabismus complex (DSC), quel est le most prominent component?

Answer 75

DVD is usually the most prominent component of the dissociated strabismus complex (DSC), but sometimes the principal dissociated movement is one of abduction (dissociated horizontal deviation, DHD), and occasionally it is almost entirely a torsional movement (dissociated torsional deviation, DTD).

Question 76

(Dissociated vertical deviation)

Concernant le DVD :
* Unilatéral ou Bilatéral
* Symétrique ou Asymétrique?
* Spontané ou Latent?

Answer 76

• DVD is usually bilateral but is frequently asymmetric.
• It may occur spontaneously (manifest DVD) or only when 1 eye is occluded (latent DVD).

Question 77

(Dissociated vertical deviation)

V ou F : Measurement of DVD is difficult and imprecise.

Answer 77

Vrai. Measurement of DVD is difficult and imprecise.

Question 78

(Dissociated vertical deviation)

Méthode pour quantifier/mesurer un DVD?

Answer 78

• In one method, a base- down prism is placed in front of the upwardly deviating eye while it is behind an occluder.
• The occluder is then switched to the fixating lower eye.
• The prism power is adjusted until the deviating eye shows no downward movement to refixate.
• These steps are then repeated for the other eye.
• Measurements obtained with this technique are confounded by any coexisting true hypertropia, but it does provide a rough estimate for surgical planning.

Question 79

(Dissociated vertical deviation)

Indications Tx DVD?

Answer 79

Treatment of DVD is indicated if the deviation is noticeable (generally more than 6Δ–8Δ) and occurs frequently during the day.

Question 80

(Dissociated vertical deviation)

Tx médical lorsque DVD unilatéral ou très asymétrique?

Answer 80

When DVD is unilateral or highly asymmetric, encouraging fixation by the eye with greater DVD by optically blurring the fellow eye is sometimes sufficient.

Question 81

(Dissociated vertical deviation)

Tx chirurgical d’un DVD?

Answer 81

• Surgery on the vertical muscles often improves the condition but rarely eliminates it.
• Recessions of the superior rectus muscle, ranging from 6 to 10 mm according to the size of the hypertropia, can be effective.
• If there is residual DVD after superior rectus muscle recession, inferior rectus muscle resection or plication can be performed.
• Inferior oblique muscle anterior transposition is also effective in treating DVD, especially if it is accompanied by inferior oblique muscle overaction.
• Bilateral surgery is performed whenever both eyes can fixate; asymmetric surgery is an option if the DVD is asymmetric.

Question 82

(Dissociated vertical deviation)

Pathologie à distinguer d’un DVD? Et pourquoi?

Answer 82

Because DVD can mimic OEAd, distinguishing it from overaction of the inferior oblique muscles is important, as the surgical approaches to these 2 conditions are different in most cases.