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

Epiblepharon and Mobius syndrome: a rare association

Venkateshwar B. Rao & Prashant Sahare

Department of Pediatric Ophthalmology and Strabismus, Jasti V Ramanamma Children’s Eye Care Centre, L V Prasad Eye Institute, Hyderabad, India

ABSTRACT:

Introduction: Mobius syndrome is a congenital disorder of facial diplegia associated with bilateral lateral rectus paralysis. Clinically it is characterized by a total absence of facial expression and severe esotropia with or without limb abnormalities. The purpose is to report congenital epiblepharon as a new clinical manifestation of Mobius syndrome and present the outcome related to motor alignment after hang back medial rectus recession.

Methods: Case report.

Results: A 6-month old male infant was referred for ophthalmic evaluation by Pediatrician. The child was a product of a term, uncomplicated pregnancy with a birth weight of 3500 gm. There was no history of alcohol, drug ingestion or any medications taken during pregnancy. Pediatrician evaluation records showed congenital talipes eqinovarus both foot with mild cerebral atrophy in CT scan of brain. Ophthalmic examination showed expression less face, loss of nasolabial folds, marked epicanthal folds, epiblepharon of both lower lids with mild trichiatic lashes and lagophthalmos. No corneal problems were seen. Ocular motility showed large esotropia of 50 to 60 PD by krimsky test with marked limitation of abduction in both eyes (not moving beyond midline). A forced duction test under anaesthesia revealed restriction mild in abduction. A bilateral hang back medial rectus recession of 6.5 mm from insertion was done. One week after surgery the child was orthotropic with stable alignment maintained at 26 months follow-up.

Conclusions: This case highlights the association of epiblepharon with Mobius syndrome which to our knowledge is previously unrecognized. Good cosmetic and motor alignment was achieved with hang back recession of medial rectus muscle.

1INTRODUCTION

Mobius syndrome is a congenital disorder of facial diplegia associated with bilateral sixth nerve paralysis. Neuropathological evidence indicates that Mobius is a more complex syndrome in which palsy of sixth and seventh cranial nerves is the minimum diagnostic feature.1 Clinically, it is characterized by a total absence of facial expression and severe esotropia.2 Generally horizontal eye movements are clearly abnormal and vertical eye movements are preserved. Limb malformations are also common with this syndrome.2,3 The etiology of this syndrome has not been clearly established. A number of investigators have speculated that disruption of the vascular system causes hypoxia of vulnerable tissues between 4 and 7 weeks of gestation.4 It has been proposed that Mobius syndrome, the Poland anomaly and Klippel Feil defect all result from a transient interruption during sixth week of gestation in the development of the subclavian artery and its branches.5 Even though many reports have described the various features of Mobius syndrome, only a few articles have reported the results of strabismus surgery in children.6,7 The purpose is to report congenital epiblepharon as a new clinical manifestation of Mobius syndrome and present the outcome related to motor alignment after hang back medial rectus recession.

313

Figure 1. Showing esotropia with marked abduction limitation.

Figure 2. (a) Showing epiblepharon both lower lids with trichiatic lashes. (b) Lagophthalmos with expressionless face and loss of nasolabial folds.

2METHODS

CASE REPORT: A 6-month-old infant was referred for ophthalmic evaluation by the pediatrician because of congenital esotropia. The child was a product of a term, uncomplicated pregnancy with a birth weight of 3500 grams. There was no history of any alcohol intake, or drug ingestion or any other medications taken by the mother during pregnancy. His mother was a healthy young woman with no known history of any disease in the family. After delivery an expressionless smooth face, strabismus, and inward turning of both feet were detected (congenital talipes equino varus) and advised for foot surgery by the pediatrician. Patient also had delayed milestones with slowness in general motor progression. Records of evaluation by pediatric neurologist showed mild cerebral atrophy on computed tomography scan of brain. Ultrasonography of abdomen and X-ray chest PA view were normal. Chromosomal analysis showed normal karyotype. Test for human immunodeficiency virus (HIV) and hepatitis surface antigen were negative. The patient was recommended by pediatric neurologist for early congnitive stimulation because of developmental delay.

On examination the child was fixing and following the light by moving his head. Ocular motility showed large esotropia of 50 to 60 PD by krimsky test with marked limitation of abduction in both eyes (not moving beyond midline) (Fig 1). Examination showed expressionless face, loss of nasolabial folds, lagophthalmos, epicanthal folds, epiblepharon of both lower lids with trichiatic eye lashes (Fig 2 a & b). Since the child was not co-operative for proper anterior and posterior segment examination, an examination under anaesthesia was advised. Meanwhile patient underwent surgery for congenital talipes equinovarus under general anaesthesia outside and came back for eye examination under anaesthesia. During examination under anaesthesia a forced duction test was carried out which was positive in abduction indicating tight medial recti in both the eyes. Cycloplegic refraction revealed hyperopia of 2.50 Ds in both eyes. Anterior segment and posterior

314

Figure 3. Post-op photograph showing orthotropic eyes with abduction limitation persisting.

Figure 4. Pre-op and Post-op appearance.

segment evaluation were normal. A bilateral hang back medial rectus recession of 6.5 mm was performed under general anaesthesia. One week after surgery the child was orthotropic in primary position, still with marked limitation of abduction in both the eyes (Fig 3). This alignment remained stable for two years (Fig 4).

3DISCUSSION

Mobius syndrome is probably caused by several teratogenic factors that act between the fourth and seventh weeks of the intrauterine life resulting in hypoplasia of sixth and seventh nerve nuclei and

315

atresia of supranuclear pathways. It has been proposed that Mobius syndrome, the Poland anomaly and Klippel-Feil defect all result from a transient interruption during sixth week of gestation in the development of the subclavian artery and its branches, including the basilar, vertebral and internal thoracic arteries which supply the brain, neck, pectoral muscles and upper limbs.5 The congenital paralysis of the lateral rectus muscle and the facial diplegia are the most important clinical manifestations of the syndrome.8 Epiblepharon is the presence of a fold in the skin and orbicularis of the lower lids that may cause trichiasis.9 It is usually self-limited diminishing with facial growth although surgical correction may be required in few cases where corneal problems develop.9 Mobius syndrome must be included in the differential diagnosis of congenital esotropia, as well as in Duane retraction syndrome, early onset accomodative esotropia and other causes of esotropia in infants.10 The few published results of strabismus surgery in these patients advocate surgical options in the form of bilateral medial rectus recession; bilateral medial rectus muscle recession and lateral rectus resection and transposition of vertical rectus muscles.11

4CONCLUSION

This case highlights the association of epiblepharon with Mobius syndrome which to our knowledge has not been reported previously. Good cosmetic and motor alignment was achieved with hang back recession of medial rectus muscle.

REFERENCES

1.Miller MT, Ray V, Owens P, Chen F. Moebius and Moebius like syndrome. J Pediatr Ophthalmol Strabismus 1989;26:176–88

2.Miller NR. Topical diagnosis of neuropathic ocular motility disorders. In Miller NR, editor: Walsh and Hoyt’s clinical neuro-ophthalmology. Ed 4, vol 2. Baltimore 1985, William and Wilkins.

3.Rogers OL, Hatch GF, Gray I. Mobius syndrome and Limb abnormalities. J Pediatr Ophthalmol 1977;14:134–138

4.Harbord MG, Ginn JP, Ham-Craggs MA et al. Moebius syndrome with unilateral cerebellar hypoplasia. J Med Genet 1989;26:579–582

5.Bavinck JN, Weaver DD. Subclavian artery disruption sequence. Hypothesis of a vascular etiology for Poland, Klipper-Feil and Mobius anomalies. Am J Med Genet 1986;23:903–918

6.Kubatko-Zielinska A, Krzystkowa KM. Congenital syndromes of oculomotor disturbances – diagnosis and results of surgical treatment. Klin Oczna 1995;97: 142–6

7.Abraham Spierer MD, Adiel Barak MD. Strabismus surgery in children with Mobius syndrome. J of AAPOS 2000;4:58–59

8.Cernea P, Grapa C. Congenital bilateral abducen paralysis and facial diplegia: the Moebius syndrome Oftalmologia 1991;35:79–84

9.Hayasaka S, Noda S, Setogawa T. Epiblepharon with inverted eye lashes in Japanese children. II. Surgical repairs. Br J Ophtalmol 1989; 73:128–130

10.Nelson LB, Wagner RS, Simon JW, Harley RD. Congenital esotropia. Surv Ophthalmol 1987;31:363–83.

11.Laby DM, Rosenbaum AL, Isenberg SJ, Fleck BW. Strabismus surgery in patients with Moebius syndrome: update on strabismus and pediatric ophthalmology. Proceedings of the joint ISA and AAPOS Meeting; 1994: Vancouver, Canada p.419–22

316