Orbital hypertelorism is defined as an increased distance between the medial orbital walls. This results in an increased distance between the globes and so an increase in the interpupillary distance.
Causes of hypertelorism:
(1) trisomy 13 or 21
(2) craniofacial syndromes (Apert syndrome, Crouzon syndrome, Saethre-Chotzen syndrome)
(3) other syndromes including, Aarskog syndrome, DiGeorge syndrome, Ehlers-Danlos syndrome, Greig syndrome, Gorlin syndrome, LEOPARD syndrome, Loeys-Dietz syndrome, Noonan syndrome, Sotos syndrome, Weaver syndrome, Wolf-Hirschhorn syndrome.
(4) telecanthus-hypospadias syndrome (Opitz syndrome)
(5) mucopolysaccharidosis (Morquio syndrome)
(6) encephalocele (frontal, nasoethmoidal)
(7) nasal glioma (nasal cerebral heterotopia)
(8) congenital dacrocystocele
(9) osteopetrosis
(10) traumatic hypertelorism following facial trauma
