Temporary uniocular blindness and ophthalmoplegia associated with a mandibular block injection. A case report.

A mandibular block injection produced temporary uniocular blindness, total ophthalmoplegia, mydriasis, and ptosis of the eyelid, with diplopia developing as the sight returned. These effects lasted 25-30 minutes. The explanation offered as to the cause of the anaesthetic phenomenon is an intra-arterial injection into the maxillary artery with backflow of anaesthetic solution into the middle meningeal artery. The instantaneous blindness results from the anaesthetic agent being carried into the central artery of the retina through an anastomosis of the ophthalmic and middle meningeal arteries via the recurrent meningeal branch of the lacrimal artery. Although of short duration, the symptoms mimic a more serious carotid artery embolus occluding the ophthalmic artery. Complications of mandibular blocks have been reported in the literature, however total blindness and ophthalmoplegia are extremely rare. This case report highlights an event where individual anatomical variation of the maxillary and middle meningeal arteries has allowed anaesthetic solution to be delivered to an ectopic site.