Duane syndrome
Encyclopedia
Duane syndrome is a rare, congenital eye movement disorder
most commonly characterized by the inability of the eye
to abduct or move outwards. The syndrome was first described by Jakob Stilling
(1887) and Siegmund Türk (1896), and subsequently named after Alexander Duane
who discussed the disorder in more detail in 1905
Other names for this condition include: Duane's Retraction Syndrome (or DR syndrome), Eye Retraction Syndrome, Retraction Syndrome, Congenital retraction syndrome and Stilling-Turk-Duane Syndrome.
In addition to the above, other characteristics may or may not be present, and these include:
In about 80% of cases, only one eye is affected (with the left being predominant in a 3:1 ratio). However, in some cases, both eyes are affected, with one eye usually more affected than the other.
s, causing some eye muscles to contract when they shouldn't and other eye muscles not to contract when they should.
Alexandrakis G & Saunders RA state that:
The mechanical factors noted by Miller and Clark above are generally regarded as arising secondary to loss of innervation. During corrective surgery fibrous attachments have been found connecting the horizontal recti and the orbital walls and fibrosis of the lateral rectus has been confirmed by biopsy. This fibrosis can result in the lateral rectus being 'tight' and acting as a tether or leash. Co-contraction of the medial and lateral recti allows the globe to slip up or down under the tight lateral rectus producing the up and down shoots characteristic of the condition.
), Goldenhar syndrome
, autism
, heterochromia
, and thalidomide
-induced embryopathy.
Type A: Limited abduction and less limited adduction (as described originally by Duane).
Type B: Limited abduction but normal adduction, and
Type C: In which limitation of adduction is greater than limitation of abduction, giving rise to a divergent deviation and a head posture in which the face is turned away from the side of the affected eye.
Type I: Marked limitation of abduction (corresponds to Brown's Type B) explicable by maximum innervation reaching the lateral rectus only when the affected eye is adducted.
Type II: Limitation of adduction (corresponds to Brown's Type C)which Hubel explains as being caused by co-innervation of both medial and lateral recti on attempted adduction, and
Type III: Limitation of both adduction and abduction (corresponds to Brown's Type A) which Hubel explains as due to co-contraction, accompanied by a loss of innervation to the lateral rectus on attempted abduction.
is uncommon and, where present, rarely dense. This can be treated with occlusion, and any refractive error can also be corrected.
Duane syndrome cannot be cured, as the "missing" cranial nerve cannot be replaced, and traditionally there has been no expectation that surgery will result in any increase in the range of eye movement. Surgical intervention, therefore, has only been recommended where the patient is unable to maintain binocularity, where they are experiencing symptoms, or where they are forced to adopt a cosmetically unsightly or uncomfortable head posture in order to maintain binocularity. The aims of surgery are to place the eye in a more central position and, thus, place the field of binocularity more centrally also, and to overcome or reduce the need for the adoption of an abnormal head posture. Occasionally surgery is not needed during childhood, but becomes appropriate later in life, as head position changes (presumably due to progressive muscle contracture
).
The late Dr. Arthur Rosenbaum at UCLA championed the use of Vertical Rectus Transposition surgery. He reported significant increases in lateral eye movements in many cases. The VRT realigned muscles work with the good medial muscle to provide a "tripod" of musculature for the eye; the newly moved muscles provide torque and tension against the medial muscle, which is what allows for the central alignment. And, because they are "working" muscles, they also may allow for some range of lateral movement in their new positions. Morad et al. report the use of a similar approach in Duane's Type C.
Prominent down- or upshoots may be treated with a special form of muscle surgery, a "Y-splitting" procedure, often combined with a recession
.
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
most commonly characterized by the inability of the eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
to abduct or move outwards. The syndrome was first described by Jakob Stilling
Jakob Stilling
Jakob Stilling was a German ophthalmologist from Kassel. He studied medicine at several locations including Paris and Würzburg, and obtained his doctorate in 1865. In 1867 he became an eye doctor in Kassel, and later furthered his education in ophthalmic medicine at Paris, Berlin, Vienna and Turin...
(1887) and Siegmund Türk (1896), and subsequently named after Alexander Duane
Alexander Duane
Alexander Duane was an American ophthalmologist who was a native of Malone, New York. He studied medicine at the College of Physicians and Surgeons...
who discussed the disorder in more detail in 1905
Other names for this condition include: Duane's Retraction Syndrome (or DR syndrome), Eye Retraction Syndrome, Retraction Syndrome, Congenital retraction syndrome and Stilling-Turk-Duane Syndrome.
Characteristics
As described by Duane, the characteristic features of the syndrome are:- Limitation of abduction (outward movement) of the affected eye.
- Less marked limitation of adductionAdductionAdduction is a movement which brings a part of the anatomy closer to the middle sagittal plane of the body. It is opposed to abduction.-Upper limb:* of arm at shoulder ** Subscapularis** Teres major** Pectoralis major** Infraspinatus...
(inward movement) of the same eye. - Retraction of the eyeballHuman eyeThe human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
into the socket on adduction, with associated narrowing of the palpebral fissure (eye closing) - Widening of the palpebral fissure on attempted abduction. (N.B. Mein and Trimble point out that this is "probably of no significance" as the phenomenon also occurs in other conditions in which abduction is limited).
- Poor convergence
- A face turn to the side of the affected eye to compensate for the movement limitations of the eye(s) and to maintain binocular visionBinocular visionBinocular vision is vision in which both eyes are used together. The word binocular comes from two Latin roots, bini for double, and oculus for eye. Having two eyes confers at least four advantages over having one. First, it gives a creature a spare eye in case one is damaged. Second, it gives a...
. - Eye is 45ﾟ to left or right, resulting in "correct movement", but wrong placing of eye. (i.e. when an unaffected eye looks to the right, the affected eye looks straight forward, and when the unaffected eye looks straight forward, the affected eye looks to the left)
In addition to the above, other characteristics may or may not be present, and these include:
- Elevation or 'upshoot' of the affected eye on adduction. More rarely, 'down shoots' can also occur.
- Head movements to compensate for loss of eye movement when attempting to view an object outside of binocular viewing range (which may be very narrow).
- Absence of diplopiaDiplopiaDiplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
: Few patients with the syndrome complain of diplopia when their eyes are misaligned.
In about 80% of cases, only one eye is affected (with the left being predominant in a 3:1 ratio). However, in some cases, both eyes are affected, with one eye usually more affected than the other.
Causes
DS is a miswiring of the eye muscleMuscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s, causing some eye muscles to contract when they shouldn't and other eye muscles not to contract when they should.
Alexandrakis G & Saunders RA state that:
This view is supported by the earlier work of Hotchkiss et al. who reported on the autopsy findings of two patients with Duanes syndrome. In both cases the sixth cranial nerve nucleus was absent, as was the sixth nerve, and the lateral rectus muscle was innervated by the inferior division of the third or oculomotor cranial nerve. This misdirection of nerve fibres results in opposing muscles being innervated by the same nerve. Thus, on attempted abduction, stimulation of the lateral rectus via the oculomotor nerve will be accompanied by stimulation of the opposing medial rectus via the same nerve; a muscle which works to adduct the eye. Thus, co-contraction of the muscles takes place, limiting the amount of movement achievable and also resulting in retraction of the eye into the socket.
In most cases, the abducens nucleus and nerve are absent or hypoplastic, and the lateral rectus muscle is innervated by a branch of the oculomotor nerve. However, there may be contributing mechanical abnormalities
The mechanical factors noted by Miller and Clark above are generally regarded as arising secondary to loss of innervation. During corrective surgery fibrous attachments have been found connecting the horizontal recti and the orbital walls and fibrosis of the lateral rectus has been confirmed by biopsy. This fibrosis can result in the lateral rectus being 'tight' and acting as a tether or leash. Co-contraction of the medial and lateral recti allows the globe to slip up or down under the tight lateral rectus producing the up and down shoots characteristic of the condition.
Epidemiology
Most patients are diagnosed by the age of 10 years and DS is more common in girls (60 percent of the cases) than boys (40 percent of the cases). A recent French study reports the following findings:Around 10-20% of cases are familial; these are more likely to be bilateral than non-familial Duane syndrome. Duane syndrome has no particular race predilection. While usually isolated to the eye abnormalities, Duane syndrome can be associated with extraocular problems (so-called "Duane's Plus"), including cervical spine abnormalities (Klippel-Feil syndrome
The incidence of this syndrome in the population of strabismic patients was 1.9%. The number of women affected was 83 (53.5%). The syndrome was unilateral in 121 cases (78.1%). The left eye (71.9%) was affected more frequently than the right.
Klippel-Feil syndrome
Klippel–Feil syndrome is a rare disease, initially reported in 1912 by Maurice Klippel and André Feil from France, characterized by the congenital fusion of any 2 of the 7 cervical vertebrae....
), Goldenhar syndrome
Goldenhar syndrome
Goldenhar syndrome is a rare congenital defect characterized by incomplete development of the ear, nose, soft palate, lip, and mandible. It is associated with anomalous development of the first branchial arch and second branchial arch...
, autism
Autism
Autism is a disorder of neural development characterized by impaired social interaction and communication, and by restricted and repetitive behavior. These signs all begin before a child is three years old. Autism affects information processing in the brain by altering how nerve cells and their...
, heterochromia
Heterochromia
In anatomy, heterochromia refers to a difference in coloration, usually of the iris but also of hair or skin. Heterochromia is a result of the relative excess or lack of melanin...
, and thalidomide
Thalidomide
Thalidomide was introduced as a sedative drug in the late 1950s that was typically used to cure morning sickness. In 1961, it was withdrawn due to teratogenicity and neuropathy. There is now a growing clinical interest in thalidomide, and it is introduced as an immunomodulatory agent used...
-induced embryopathy.
Classification
Two different classification systems have been proposed, by Brown and by Huber, of which Brown's remains in more common clinical use.Brown's classification
Brown classified the condition using the following three sub-types, based upon clinical observations:Type A: Limited abduction and less limited adduction (as described originally by Duane).
Type B: Limited abduction but normal adduction, and
Type C: In which limitation of adduction is greater than limitation of abduction, giving rise to a divergent deviation and a head posture in which the face is turned away from the side of the affected eye.
Huber's classification
Huber's classification system was based upon electromyographical examinations:Type I: Marked limitation of abduction (corresponds to Brown's Type B) explicable by maximum innervation reaching the lateral rectus only when the affected eye is adducted.
Type II: Limitation of adduction (corresponds to Brown's Type C)which Hubel explains as being caused by co-innervation of both medial and lateral recti on attempted adduction, and
Type III: Limitation of both adduction and abduction (corresponds to Brown's Type A) which Hubel explains as due to co-contraction, accompanied by a loss of innervation to the lateral rectus on attempted abduction.
Differential diagnosis
Disorders similar in presentation to Duane syndrome can be acquired as a result of trauma, or following localised infection of the orbit leading to inflammation and consequent mechanical restrictions of eye movement. In such cases a full case history will usually help in distinguishing between these conditions. In the clinical setting, the principal difficulties in differential diagnosis arise as a consequence of the very early age at which patients with this condition first present. The clinician must be persistent in examining abduction and adduction, and in looking for any associated palpebral fissure changes or head postures, when attempting to determine whether what often presents as a common childhood squint is in fact Duane syndrome. Fissure changes, and the other associated characteristics of Duane's such as up or down shoots and globe retraction, are also vital when deciding whether any abduction limitation is the result of Duane's and not a consequence of VI or abducens cranial nerve palsy.Treatment
The majority of patients remain symptom free and able to maintain binocularity with only a slight face turn. AmblyopiaAmblyopia
Amblyopia, also known as lazy eye, is a disorder of the visual system that is characterized by a vision deficiency in an eye that is otherwise physically normal, or out of proportion to associated structural abnormalities of the eye...
is uncommon and, where present, rarely dense. This can be treated with occlusion, and any refractive error can also be corrected.
Duane syndrome cannot be cured, as the "missing" cranial nerve cannot be replaced, and traditionally there has been no expectation that surgery will result in any increase in the range of eye movement. Surgical intervention, therefore, has only been recommended where the patient is unable to maintain binocularity, where they are experiencing symptoms, or where they are forced to adopt a cosmetically unsightly or uncomfortable head posture in order to maintain binocularity. The aims of surgery are to place the eye in a more central position and, thus, place the field of binocularity more centrally also, and to overcome or reduce the need for the adoption of an abnormal head posture. Occasionally surgery is not needed during childhood, but becomes appropriate later in life, as head position changes (presumably due to progressive muscle contracture
Contracture
A muscle contracture is a permanent shortening of a muscle or joint.. It is usually in response to prolonged hypertonic spasticity in a concentrated muscle area, such as is seen in the tightest muscles of people with conditions like spastic cerebral palsy....
).
Surgical approaches
In types A and B the most commonly adopted approach remains the recession of the medial recti of the affected eye, or of both eyes where the condition is bilateral. In type C, recession of the lateral recti is the method of choice.The late Dr. Arthur Rosenbaum at UCLA championed the use of Vertical Rectus Transposition surgery. He reported significant increases in lateral eye movements in many cases. The VRT realigned muscles work with the good medial muscle to provide a "tripod" of musculature for the eye; the newly moved muscles provide torque and tension against the medial muscle, which is what allows for the central alignment. And, because they are "working" muscles, they also may allow for some range of lateral movement in their new positions. Morad et al. report the use of a similar approach in Duane's Type C.
Prominent down- or upshoots may be treated with a special form of muscle surgery, a "Y-splitting" procedure, often combined with a recession
Recession
In economics, a recession is a business cycle contraction, a general slowdown in economic activity. During recessions, many macroeconomic indicators vary in a similar way...
.
See also
- Eye care professionalEye care professionalAn eye care professional is an individual who provides a service related to the eyes or vision. It is a general term that can refer to any healthcare worker involved in eye care, from one with a small amount of post-secondary training to practitioners with a doctoral level of education.-Current...
- Convergence insufficiencyConvergence insufficiencyConvergence insufficiency or Convergence Disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by an inability of the eyes to turn towards each other, or sustain convergence.-Symptoms:...
- DiplopiaDiplopiaDiplopia, commonly known as double vision, is the simultaneous perception of two images of a single object that may be displaced horizontally, vertically, or diagonally in relation to each other...
- Pediatric ophthalmologyPediatric ophthalmologyPediatric ophthalmology is a sub-speciality of ophthalmology concerned with eye diseases, visual development, and vision care in children.-Training:...
- StrabismusStrabismusStrabismus is a condition in which the eyes are not properly aligned with each other. It typically involves a lack of coordination between the extraocular muscles, which prevents bringing the gaze of each eye to the same point in space and preventing proper binocular vision, which may adversely...
- International Orthoptic AssociationInternational Orthoptic AssociationThe International Orthoptic Association represents over 20,000 orthoptists, in over 20 countries.- History :The International Orthoptic Association was formed in 1967 after the first International Orthoptic Congress. The British Orthoptic Association were the founding members. - Registration and...
- EyepatchEyepatchAn eyepatch or eye pad is a small patch that is worn in front of one eye. It may be a cloth patch attached around the head by an elastic band or by a string, or an adhesive bandage. It is often worn by people to cover a lost or injured eye, but it also has a therapeutic use in children for the...
- ExotropiaExotropiaExotropia is a form of strabismus where the eyes are deviated outward. It is the opposite of esotropia. People with exotropia often experience crossed diplopia. Intermittent exotropia is a fairly common condition. "Sensory exotropia" occurs in the presence of poor vision...
- EsotropiaEsotropiaEsotropia is a form of strabismus, or "squint", in which one or both eyes turns inward. The condition can be constantly present, or occur intermittently, and can give the affected individual a "cross-eyed" appearance...
- Orthoptist
- HaploscopeHaploscopeA haploscope is an optical device for presenting one image to one eye and another image to the other eye. The word derives from two Greek roots: haploieides, single and skopeo, to view. The word is often used interchangeably with stereoscope, but it is more general than that. A stereoscope is a...
- GlassesGlassesGlasses, also known as eyeglasses , spectacles or simply specs , are frames bearing lenses worn in front of the eyes. They are normally used for vision correction or eye protection. Safety glasses are a kind of eye protection against flying debris or against visible and near visible light or...