Syndromes

Question 1

CONGENITAL CRANIAL DYSINNERVATION DISORDERS

Answer 1

Duane retraction syndrome, Möbius syndrome, Congenital fibrosis of the extraocular muscles, Strabismus fixus, Marcus Gunn jaw-winking syndrome, horizontal gaze palsy and progressive scoliosis, many cases of congenital ptosis, congenital fourth cranial nerve palsy and congenital facial nerve palsy

Question 2

Strabismus fixus

Answer 2

both eyes are fixed by fibrous tightening of the medial recti (convergent strabismus fixus) or the lateral recti (divergent strabismus fixus). Congenital and acquired forms.

Question 3

Congenital fibrosis of the extraocular muscles

Answer 3

non-progressive, usually AD, bilateral ptosis and restrictive external ophthalmoplegia, CFEOM1 is the most common. KIF21A gene. Vertical movements are severely restricted with inability to elevate the eyes above the horizontal plane. In the primary position each eye is fixed below the horizontal by about 10°, with a corresponding compensatory chin elevation. The degree of residual horizontal movement varies markedly

Question 4

Möbius syndrome

Answer 4

sporadic. congenital non-progressive bilateral sixth and seventh cranial nerve palsies (abnormality of the brainstem) ○ 5, 8, 10 and 12 cranial nerves may also be affected ○ May Limb anomalies and mild mental handicap ○ Horizontal gaze palsy (50%) ○ Occasionally, third and fourth nerve palsy and ptosis

Question 5

MONOCULAR ELEVATION DEFICIENCY

Answer 5

double elevator palsy, sporadic, tight or contracted inferior rectus muscle or a hypoplastic or ineffective superior rectus muscle. Profound inability to elevate one eye across the horizontal plane, from abduction to adduction, with orthophoria in the primary position in about one-third of cases. Chin elevation may be present

Question 6

Duane - definition

Answer 6

hypoplastic sixth nerve nucleus, with anomalous innervation of the lateral rectus by fibres from the third nerve. Often bilateral

Question 7

Duane - systemic associations

Answer 7

deafness, external ear abnormalities, speech disorder and skeletal abnormalities

Question 8

Duane type I

Answer 8

the most common, ○ Limited or absent abduction. ○ ○ In the primary position, straight or slight esotropia.

Question 9

Duane type II

Answer 9

least common, ○ Limited adduction. ○ In primary position, straight or slight exotropia

Question 10

Duane type III

Answer 10

Limited adduction and abduction. ○ In the primary position, straight or slight esotropia

Question 11

Duane - other motility disturbances

Answer 11

• A face turn, compensatory head posture • Retraction of the globe on adduction • An up-shoot or down-shoot in adduction • Deficiency of convergence in which the affected eye remains fixed in the primary position while the unaffected eye is converging • Amblyopia, when present, is usually the result of anisometropia rather than strabismus.

Question 12

Duane - treatment

Answer 12

Unilateral or bilateral muscle recession or transposition of the vertical recti. The lateral rectus of the involved side should not be resected, as this increases retraction.