Basilar artery origin of an orbital artery - A rare variant and review of the embryology of the orbital arterial supply.

We present a patient with separation of the arterial supply to the globe and the extra-ocular muscles. The ophthalmic artery originates from the typical adult location and supplies only the globe. Arising from the basilar artery was a branch that supplies the extra-ocular muscles. There was no apparent connection between these vessels around the optic nerve and no evidence of supply from the external carotid artery. We discuss the embryology of the ophthalmic artery from the point of view of Padget and Lasjaunias and offer our opinion on the on-going controversy. We believe this is the first case to highlight the trigeminal-primitive maxillary-stapedial anastamotic pathway.