Orbit

Orbitomalar/zygomatic arch hypoplasia is present in all patients with Treacher Collins Syndrome.

Defects include:

• The incomplete or absent zygomatic arch along with an open lower orbital rim will give rise to a downward slanting of the eye.

• Coloboma is highly specific for Treacher Collins Syndrome, however it is not present in every case.

• Lacrimal system anomalies are also common, this includes atresia of the lacrimal puncta and canaliculi.