Ocular muscle extorsion and congenital orbital malformation

Abstract

The pseudo-ectopic macular syndrome with ocular extorsion has been described in France by Weiss. There is a rotation of the four muscular insertions without change of the perpendicular axis between horizontal and vertical muscles. This syndrome is found very often in congenital orbital malformations. We have seen it in Treacher-Collins-Franceschetti syndrome, in craniofacial stenosis (Crouzon disease), in hypertelorism and in orbital dystopy (plagiocephaly). After orbital surgery there is no change in the ocular deviation. According to our opinion this orbital structural abnormality with antimongoloid palpebral apertures is to blame for the displacement of the ocular muscles. Patients with maxillary hypoplasia as in Crouzon's disease or in Treacher-Collins syndrome have an associated antimongoloid slant of the palpebral fissures and overaction of the inferior oblique muscles, resulting in a V pattern. In the same way these antimongoloid palpebral fissures are seen in hypertelorism because the divergence of the orbits is more pronounced in the frontal sector than in the maxillary sector. In plagiocephalies, the orbital aperture is oval with its long axis in the inferior and medial direction. Occasionally this antimongoloid fissure is found in orbital dystopy.