DUANES RETRACTION SYNDROME

INTRODUCTION

Forms a part of a group of conditions called CONGENITAL CRANIAL DYSINNERVATION DISORDERS (CCDD) which occur due to result of developmental errors in the innervation of ocular and facial muscles

Congenital miswiring of the medial and lateral rectus muscles

Described by Stilling in 1887 and Turk in 1896 Hence in European literature - referred to as the

Stilling-Turk-Duane syndrome after it’s early describers.

In 1905, Duane emphasized that the retraction of the globe is an essential clinical feature of this syndrome, thus the term “Duane’s Retraction Syndrome” is deeply entrenched

PATHOGENESIS 1. Myogenic Theory: This theory, suggested by earlier studies, indicates

there is fibrosis or inelasticity of the lateral rectus muscles and that the medial rectus muscle inserts abnormally far posteriorly.

Andrews, Caroline V., David G. Hunter, and Elizabeth C. Engle. Duane Syndrome. GeneReviews. http://www.ncbi.nlm.nih.gov/books/NBK1190/. [July 14, 2012].

2. Neurogenic Theory: A disturbance in embryologic development

between weeks 4-8 results in an absent abducens nerve with anomalous innervations of the lateral rectus muscle by a branch of the oculomotor nerve.Simultaneous activation of the medial and lateral rectus muscles, as demonstrated by EMG studies, may be the cause of global retraction

Hotchkiss, Mary G., Neil R. Miller, Arthur W. Clark, and William R. Green . Bilateral Duane's Retraction Syndrome A Clinical-Pathologic Case Report. Arch Ophthalmol. 1980; 98: 870-874

TYPE 1

-Poor abduction, good adduction

-Agenesis of 6th nerve-3rd nerve split innervate LR, MR-adduction intact as Most of the nerve goes to MR

TYPE 2

-Poor adduction, good abduction

-6th nerve intact-3rd nerve split innervate LR, MR-Poor adduction as LR contract against MR

TYPE 3

-Poor adduction, poor abduction

-6th nerve agenesis-3rd nerve split innervate LR, MR-The split is equal

TYPE 4

-Paradoxical abduction on attempt adduction

-6th nerve agenesis-3rd nerve split innervate LR, MRMost of the nerve innervates LR-when ADD it ABD

CLASSIFICATION (HUBERS)

Type I the most common, is characterized by:    •    Limited or absent ABDUCTION.

   •    Normal or mildly limited adduction.   •    In the primary position, straight or slight esotropia.

      Type II, the least common, is characterized by:    •    Limited ADDUCTION.

   •    Normal or mildly limited abduction.   •    In primary position, straight or slight exotropia.

   Type III is characterized by:    •    Limited ADDUCTION AND ABDUCTION.

   •    In the primary position, straight or slight esotropia.

Duane’s Syndrome Type I: OSlimited abduction,

retraction in adduction

G.Vicente

Duane’s Syndrome Type II: OSlimited adduction

retraction in adduction

G.Vicente

Duane’s Syndrome Type III: OSlimited adduction and abduction

retraction in adduction

G.Vicente

EPIDEMIOLOGY Prevalence of about 1/1000 in general population Females (60%) > Males (40%) Accounts for up to 4% of all strabismus cases Most common type of congenital aberrant ocular

innervation 80% of cases occur unilaterally, with a LE

predominance *

*Murillo-Correa, Claudia E., Veronica Kon-Jara, Elizabeth C. Engle, and Juan C. Zenteno. Clinical features associated with an I126M α2-chimaerin mutation in a family with autosomal dominant Duane retraction syndrome. J AAPOS. 2009; 13 (3): 245-248.National Human Genome Research Institute. Learning About Duane Syndrome. Genome.gov. http://www.genome.gov/11508984

70% of cases are isolated30% of cases are associated with other congenital anomalies

1. ISOLATED CASES 90% occur sporadically and are commonly

unilateral Remaining 10% are inherited and these are

commonly bilateral

2. SYNDROMIC FORMS Okihiro's syndrome: Duane syndrome and radial

ray defects Goldenhar syndrome: malformation of the jaw,

cheek and ear, usually on one side of the face Wildervanck syndrome: Duane syndrome,

Klippel-Feil anomaly, and deafness Moebius syndrome : congenital paresis of facial

and abducens cranial nerves Holt-Oram syndrome: abnormalities of the

upper limbs and heart Morning Glory syndrome: abnormalities of the

optic disc

CLINICAL FEATURES Characterized by some or all of the following :

1) Complete, or less often partial, absence of outward movement (abduction) of the affected eye

2) Partial, or rarely complete, deficiency of inward movement (adduction) of the affected eye

3) Retraction of the affected eye into the orbit when it is adducted

4) Partial closure of the eyelids (pseudoptosis) of the affected eye when it is adducted

5) A sharply oblique movement of the affected eye, either down and in (downshoot) or up and in (upshoot ), when it is adducted

6) Deficiency of convergence, with the affected eye remaining fixed in the primary position while the other eye is converging

7) Abnormal head posture is adopted to search for the direction of gaze where there is no misalignment of the two eyes in order to obtain binocularity. Longstanding torticollis (since birth) leads commonly to craniofacial asymmetry

Strabismus: 76% of individuals have frank strabismus in primary gaze

Poor Binocular Vision Reviews of DRS patients have shown

hypermetropia of greater than +1.50 in 71% of the patients

Amblyopia occurs in about 10% of individuals and will respond to standard therapy if detected early

Anisometropia

D/D Congenital sixth nerve palsy Infantile esotropia Mobius syndrome

MANAGEMENTA) NON SURGICAL Spectacles or contact lenses for refractive error Prism glasses to improve the compensatory head

position Treat amblyopia with standard therapy Botulinum Toxin: botulinum toxin decreases the

amount of deviation and leash phenomenon (upshoot or downshoot of globe with adduction).

B) SURGICAL The aims of surgery are: To correct a manifest strabismus To centralize the field of binocular single vision, To overcome or reduce the need for a large

compensatory head posture

AVOID LATERAL RECTUS RESECTION

Surgery is indicated for the following reasons:

Decompensation, giving rise to manifest strabismus

Abnormal head postureSevere globe retraction with or without up-

shoot and down-shoot

For types 1 and 3 with head turn: recession of medial rectus muscle or horizontal transposition of vertical rectus muscles

For types 1 and 3 with Leash Phenomenon and/or severe globe retraction: recession of both medial and lateral rectus muscles with possible Y-splitting of the lateral rectus muscle

. Kekunnaya R, Kraft S, Rao V, Velez F, Sachdeva V, Hunter D. Surgical management of strabismus in Duane retraction syndrome. Journal of American Association for Pediatric Ophthalmology and Strabismus. 2015;19(1):63-69.

For type 2 with head turn and fixation with uninvolved eye: recession of ipsilateral lateral rectus muscle

For type 2 with head turn and fixation with involved eye: recession of contralateral lateral rectus muscle

For type 2 with Leash Phenomenon: recession of lateral rectus muscle with possible Y-splitting

Complications of Surgery

Undercorrection of primary position esotropia and the compensatory head turn

Overcorrection leading to secondary exotropia New vertical deviations can occur after vertical

rectus transposition procedures

BROWNS SYNDROME In 1950, Harold W. Brown first published on an unusual

motility disorder, characterized by limited ocular elevation in adduction

Brown attributed the limited elevation to a short or tight anterior superior oblique tendon sheath. He termed this as superior oblique tendon sheath syndrome

He further hypothesized that the short tendon sheath was due to a complete congenital paresis of the ipsilateral inferior oblique muscle and secondary to sheath contracture.

In the mid 1970s, Parks and colleagues reported that a tight tendon sheath was not the cause of Brown syndrome; instead, it was a tight or short superior oblique tendon.

Subsequent studies confirmed the cause of the syndrome to be a tight or inelastic superior oblique tendon

ETIOPATHOGENESIS Brown syndrome can be divided into congenital and acquired.

CONGENITAL BROWN SYNDROME

Superior oblique Brown syndrome A tight or inelastic superior oblique tendon muscle complex

would restrict ocular elevation in adduction. Many theories for the cause of the tight or inelastic tendon exist.

Helveston theory of abnormal telescoping mechanism

Earlier , it was believed that the superior oblique tendon moves through the trochlea much like a rope through a pulley.

Through a detailed anatomical study, Helveston showed that the superior oblique tendon appears to move in part by a telescoping or slide-by fashion with only the central fibers of the tendon making the total excursion

Congenital Brown syndrome could be caused by a developmental abnormality of the elastic-crossed fibers that normally allow the telescoping movement of the central tendon fibers.

Helveston EM, Merriam WW, Ellis FD, Shellhamer RH, Gosling CG. The trochlea. A study of the anatomy and physiology. Ophthalmology. 1982 Feb. 89(2):124-33

Wright hypothesis of congenital inelastic superior oblique muscle-tendon complex

In 1999, Wright described a computer simulation of Brown syndrome, using two specific models, as follows:

(1) a short superior oblique tendon, and (2) a stiff superior oblique tendon (stretched sensitivity). The computer model showed that a tight or inelastic muscle-

tendon complex was the best fit for the Brown syndrome pattern of deviation.

Wright KW. Brown's syndrome: diagnosis and management. Trans Am Ophthalmol Soc. 1999. 97:1023-109.

Non superior oblique Brown syndrome Nonsuperior oblique Brown syndrome or pseudo-Brown

syndrome is a restriction of ocular elevation in adduction caused by pathology other than an abnormality of the superior oblique muscle or tendon.

Congenital bands: Inferior orbital fibrous adhesions or fibrous bands to the posterior globe are rare causes of restriction of elevation in adduction.

Congenital inferior location of lateral rectus muscle pulley: Rare case of congenital Brown syndrome are caused by congenital inferior location of the lateral rectus muscle. In these cases, the limitation of elevation in adduction is caused by the stiff lateral rectus muscle that is congenitally located inferior to the normal position.

ACQUIRED BROWN SYNDROME

Acquired superior oblique Brown syndrome Abnormal telescoping mechanism: Due to one of the

following: vascular dilatation of the tendon sheath vessels and local edema occurring within the confined area of the trochlea.

Tight or inelastic superior oblique tendon A tight superior

oblique tendon can be caused by a mass that displaces the tendon, a scleral buckling, or a superior oblique tendon tuck.

A rare acquired fibrosis of the superior oblique muscle is possibly associated with thyroid disease or an intramuscular injection of local anesthetic,

Stenosing tenosynovitis (trigger-thumb analogy theory) Chronic movement of the superior oblique tendon through

the trochlea can result in a traumatic tenosynovitis with tendon-swelling and stenosis of the surrounding tendon sheath. Trigger-thumb is a congenital or acquired constriction or stenosis of the fibrous sheath, which surrounds the tendon and causes secondary enlargement of the tendon proximal to the constriction. The combination of a sheath-stenosis and tendon swelling prevents movements of the tendon.

Superior oblique click syndrome : Inflammation produces a nodule on the superior oblique

tendon, just posterior to the trochlea. The nodule would have difficulty entering the trochlea, thus restricting tendon movement.

Peritrochlear scarring Extensive scarring around the trochlea can result in

restriction of the tendon movement in both ways, resulting in both a Brown syndrome and a superior oblique palsy (canine tooth syndrome). This can be caused by trauma, periocular surgery, and upper lid blepharoplasty with removal of periorbital fat with cautery.

Acquired nonsuperior oblique Brown syndrome

Inferior orbital fibrous adhesions to the posterior globe are caused by the following: orbital floor fracture and fat adherence syndrome associated with inferior orbital trauma.

Superior nasal orbital mass: These patients usually demonstrate a large vertical deviation in primary position often associated with exotropia. Possible causes are a glaucoma drainage implant or a neoplasm in the superior orbital quadrant.

EPIDEMIOLOGY The incidence of this condition is 1 in 450 cases of

strabismus

Approximately one in 20,000 live births.The actual incidence may be higher as many cases are asymptomatic.

There is equal predilection for both sexes in congenital Brown syndrome.

Wright noted that 5% cases are bilateral and idiopathic Brown syndrome has a higher preponderance in females (63%) and traumatic acquired Brown in males (82%).3

CLINICAL FEATURES A left Brown syndrome has the following

characteristics:    1    MAJOR SIGNS    •    Usually straight with BSV in the primary

position    •    Limited left elevation in adduction    •    Limited left elevation on upgaze is common    •    Normal left elevation in abduction    •    Absence of left superior oblique overaction    •    Positive forced duction test on elevating the globe in adduction.

   2    VARIABLE SIGNS    •    Down-shoot in adduction.

   •    Hypotropia in primary position.   •    AHP with chin elevation and ipsilateral head tilt

Brown syndrome has also been classified as a) mild – no hypotropia in primary or adducted position b) moderate – hypotropia in adducted position c) severe – hypotropia in primary position

A third classification was proposed by Jampolsky a) True Brown syndrome – no hypotropia in primary position or down gaze b) Brown syndrome plus – vertical deviation in primary

position or adduction ± head posture.

D/D 1)Isolated inferior oblique palsy: This is characterized by

overaction of the superior oblique muscle and positive Parks’ three step test. Forced duction test is free in inferior oblique palsy.

2. Double elevator palsy: Limitation of elevation is present in both adduction and abduction. In addition the patients have ptosis or pseudoptosis.

3. Congenital fibrosis syndrome: The differences include restricted elevation in abduction and esotropia on attempted upgaze.

4.Blow out fracture of the inferior orbital wall: The elevation deficiency is more marked in abduction. Imaging reveals a fracture and there may be associated enophthalmos.

5. Thyroid ophthalmopathy: The elevation deficiency is worse in abduction than adduction.

6. Adherence syndrome: During inferior oblique surgery adhesions may form due to fat prolapse and limit elevation in abduction.

MANAGEMENT The vision needs to be checked to rule out amblyopia.

Abnormal head posture if present is indicative of the presence of fusion.

Forced duction testing needs to be performed to confirm the diagnosis

Spontaneous improvement is known to occur. Hence it may be prudent to observe cases where there is no threat to binocularity.

Elevation in adduction exercises can improve the condition in congenital cases or in cases where there is intermittent Brown syndrome.

Injection of corticosteroids has been reported to improve the Brown syndrome in patients with inflammatory disease.

Systemic treatment of the underlying disease may improve cases of acquired Brown syndrome

SURGICAL MANAGEMENT

Indications

When there is a loss of binocularity, with the chance of development of amblyopia and the child does not develop an abnormal head posture, surgery is indicated.

Mild Brown syndrome needs to be observed. If there is presence of primary position hypotropia and unacceptable downshoot on adduction, surgery can be considered

Acquired cases due to the presence of a scleral explant or a glaucoma filtering valve need to be operated.

TECHNIQUES

Historical –Sheathectomy, Superior oblique and trochlear luxation

Others – Superior oblique tenectomy or tenotomy Z-tenotomy of the superior oblique Simultaneous inferior oblique recession Superior oblique tendon expander Chicken suture Superior oblique recession

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