Variability in relationships of arteries and nerves in the human orbit.

Orbits of humans were examined by dissection to study anatomic relationships of selected arteries and nerves. The usual paths of the ophthalmic artery and nasociliary nerve were superior to the optic nerve, but the ophthalmic artery crossed inferior to the optic nerve in 28% of the cases, a higher incidence than generally reported. The anterior ethmoidal artery and nerve almost invariably passed between the superior oblique and medial rectus muscles. When present, the posterior ethmoidal artery and nerve generally coursed above the superior oblique muscle.