Transactions 29th European Strabismological Association Meeting – de Faber (ed) © 2005 European Strabismological Association, ISBN 04 1537 211 9

Surgical ancorage of the lateral rectus muscle to the periosteum of the orbit: a new tool to tuckle retraction in Duane syndrome and exotropia in 3rd cranial nerve palsy

C. Schiavi, C. Bellusci, M. Fresina & E.C. Campos

Ophthalmology Service, University of Bologna, St. Orsola-Malpighi Hospital, Bologna, Italy

ABSTRACT: Objective of the present study was to evaluate the possibility of surgically eliminating of any function of the lateral rectus muscle of the affected eye in patients with Duane syndrome with globe retraction in adduction and in patients with complete 3rd cranial nerve paralysis. Surgery was based upon a technique introduced by Alan Scott which consists in anchoring the lateral rectus detached from the globe onto the periosteum of the lateral wall of the orbit with a nonabsorbable 6–0 prolene suture. Two patients with complete 3rd cranial nerve paralysis and one patient with Duane syndrome type I underwent surgery with this technique. Eye position improved in the two patients with complete 3rd cranial nerve paralysis. The patient with Duane syndrome showed disappearance of globe retraction in adduction. Additional surgery was required to correct esotropia in the patient with Duane syndrome and to improve hypotropia in one patient with 3rd cranial nerve palsy.

1INTRODUCTION

The results of surgical treatment of Duane syndrome (DS) often are disappointing. For this reason surgery is indicated only when there is a strabismus in primary position with a compensatory head turn or when there is a cosmetic problem due to a vertical displacement of the adducted eye (upshoot or down-shoot) or a narrowing of the palpebral fissure with retraction of the globe in adduction. A recession of the antagonist medial rectus muscle 6 mm should be performed to correct approximately 15PD of face turn in DS type I. If it is necessary to correct 30 PD, a further recession on the medial rectus of the other eye should be added.

In DS type II recession of the lateral rectus muscle of the involved eye or recession of both lateral rectus muscles improves the anomalous head posture. DS type III is surgically managed with recession of both horizontal muscles. The recessions must be asymmetrical, depending on the type of deviation in primary position.

Vertical displacement in adduction can be reduced with a maximal recession of both horizontal muscles (von Noorden 1992) or with a posterior fixation suture on the lateral rectus (Scott and Wong 1972).

To increase the width of insertion of the lateral rectus and to decrease the bridle effect, the lateral rectus tendon can be split into a “Y” configuration (Rogers and Bremer 1984).

Surgery for globe retraction in adduction consists of recession of the lateral rectus or maximal recession of both horizontal muscles (von Noorden 1992). But even large recessions of the lateral rectus may lack to resolve retraction in adduction, due to persisting co-contraction of the lateral and medial rectus muscles in adduction.

Surgical management of complete 3rd c.n. paralysis is problematic. Surgical options include maximal resect/recess. procedures on the horizontal muscles (Metz 1993), transposition of the lateral or vertical rectus muscles, tenotomy of the superior oblique or superior oblique transposition,

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adducting traction sutures, orbital anchoring sutures (Salazar-Leon, Ramirez-Ortiz, Salas-Vargas 1998, Goldberg, Rosenbaum, Tong 2000), eye muscle prostheses derived from silicone bands (Scott, Miller, Collins 1992, Bicas 1991). Goods results with transposition surgery on the rectus muscles can be obtained when a vertical rectus muscle of the affected eye, the superior rectus, is still functioning, like happens in the paralysis of the inferior division of the 3rd c.n. (Kushner 1999).

In a complete 3rd c.n. paralysis the eye often maintains a fixed divergent position despite a maximal recession of the lateral rectus, due to residual overaction of this muscle.

Objective of the present study was to reduce or eliminate any function of the lateral rectus in DS patients with retraction in adduction and in patients with complete 3rd c.n. paralysis by surgically anchoring to the orbit the lateral rectus muscle detached from the globe with a technique previously described by Alan B. Scott M.D. in a personal comunication.

2MATERIALS AND METHODS

Three patients took part in the present study:

1.A 5 years old girl with DS type I of the left eye, who presented with left eye 15 PD esotropia in the primary position and globe retraction in adduction.

2.A 5 years old boy with complete congenital 3rd left c.n. palsy presenting with 45 PD left eye exotropia and 20 PD left eye hypotropia in the primary position after bilateral large lateral rectus muscle recession.

3.A 8 years old boy with complete congenital 3rd right c.n. palsy presenting with 35 PD right eye exotropia and 15 PD righr eye hypotropia in the primary position after bilateral lateral rectus muscle recession.

Surgery consisted in anchoring the LR of the affected eye detached from the globe to the orbit with two 6–0 prolene non-absorbable sutures. The radial incisions of the conjunctiva were extended 5 mm or more. Two single armed prolene non-absorbable sutures were inserted and locked to the lower and upper edges of the lateral rectus muscle close to the insertion. The muscle tendon was dissected from the globe with curved Stevens tenotomy scissors. A speculum of Pannarale or Schepens or a similar shaped retractor was placed to expose the lateral orbital wall behind the lateral conjunctival fornix (about 20 mm from the limbus). The two prolene sutures were passed through the tissue covering the medial side of the lateral wall of the orbit and tied with a triple knot.

Additional surgery was required in patient 1 and in patient 3. In patient 1, 6 mm recession of the right medial rectus muscle and 8 mm recession of the left medial rectus muscle were performed in the same session to correct esotropia. In patient 3, a transposition of the right superior oblique to the insertion of the medial rectus was added to the orbital anchoring procedure of the right lateral rectus to correct hypotropia.

The follow-up ranged from 6 months (patient 1) to 15 months (patient 3).

3RESULTS

In patient 1 (DS type I) an improvement of globe retraction and of the up-shoot in adduction was obtained. After surgery that consisted in bimedial recession and left lateral rectus anchorage to the periosteum, adduction of the left eye decreased and limitation of abduction of the same eye increased.

In patient 2 (3rd left c.n. palsy previously operated on with bilateral recession of the lateral rectus muscle) exotropia of the left eye improved of 20 PD in the primary position, and abduction, though reduced, persisted. The vertical deviation of the left eye was unchanged.

Patient 3 (right 3rd c.n. palsy previously operated on with bilateral large recession of the lateral rectus muscle) showed orthotropia in the primary position, with some degrees of adduction of the right eye and limitation of abduction of the same eye. In this case a transposition of the right superior oblique to the insertion of the paralytic medial rectus muscle was added to the anchorage of the

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lateral rectus to the orbit. This probably explains the improvement of adduction and disappearence of hypotropia in the right eye.

4CONCLUSIONS

Orbital anchoring sutures with prolene are widely used in plastic reconstructive surgery. This material has proved to be biocompatible with a low tendency to late failure. The results of this study confirm that surgical anchorage of the lateral rectus muscle to the periosteum of the orbit with a prolene suture is a safe, simple, and effective technique in reducing the effects of co-contraction of the horizontal muscles in adduction in patients with Duane syndrome, and in improving eye position in fixed divergent strabismus secondary to complete 3rd c.n. paralysis.

In Duane syndrome type I additional surgery can be required to correct esotropia which may worsen after detaching the lateral rectus of the affected eye from the globe. Moreover, transpostion of vertical recti on the insertion of lateral rectus muscle may improve the abduction of the eye.

In complete oculomotor palsy transposition of the superior oblique to the paralytic medial rectus improves the surgical results.

REFERENCES

1.Bicas, H.E.A. 1991. J. Pediatr. Ophthalmol. Strabismus, 28: 10–13

2.Goldberg, R.A., Rosenbaum, A.L., Tong, J.T. 2000. Arch. Ophthalmol.118: 431–437

3.Kushner, B.J. 1999. Surgical treatment of paralysis of the inferior division of the oculomotor nerve. Arch. Ophthalmol. 117: 485–489

4.Metz, H. 1993. J. Pediatr. Ophthalmol. Strabismus, 30: 346–353

5.Noorden, G.K. von 1992. Recession of both horizontal recti muscles in Duane’s retraction syndrome with elevation and depression of the adducted eye. Am. J. Ophthalmol. 114: 311–314

6.Rogers, G.K., Bremer, D.L. 1984. Surgical treatment of the up-shoot and down-shoot in Duane’s retraction syndrome. Ophthalmology, 91: 1380–1383

7.Salazar-Leon, J.A., Ramirez-Ortiz, M.A., Salas-Vargas, M. 1988. The surgical correction of paralytic strabismus using fascia lata. J. Pediatr. Ophthalmol. Strabismus, 35: 27–32

8.Scott, A.B., Wong, G.Y. 1972. Duane’s syndrome: an electromyographic study. Arch. Ophthalmol. 87: 140–147

9.Scott, A.B., Miller, J.M., Collins, C.C. 1992. J. Pediatr. Ophthalmol. Strabismus, 29: 216–218

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