A case is reported in which coronal laminagrams during pneumoencephalography revealed air in the sheaths of the intraorbital portion of the optic nerves. This was probably due to an unusual anatomic variant since attempts to repeat this in other patients were not successful. The intraorbital course of the optic nerves in this patient is demonstrated and presented in serial laminagrams.
Tenner MS, Trokel SL. Demonstration of the Intraorbital Portion of Optic Nerves by Pneumoencephalography. Arch Ophthalmol. 1968;79(5):572-573. doi:10.1001/archopht.1968.03850040574013