optic nerves


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Related to optic nerves: Cranial nerves, Olfactory nerves

optic nerves

The 2nd of the 12 pairs of CRANIAL NERVES which emerge directly from the brain. The optic nerves are bundles of about one million nerve fibres originating in the RETINAS and connecting these to the brain. Each nerve passes through a channel in the bone at the back of the eye sockets (orbits) to reach the inside of the skull and to join with, and partially cross over, its fellow in the OPTIC CHIASMA.
References in periodicals archive ?
Optical coherence tomography of the optic nerve head and retinal nerve fiber layer verified a normal nerve fiber layer in both eyes.
Several had MRI scans, spinal taps, and computerized analysis of their optic nerve.
He also revealed how his daughter is suffering from hypotonia and optic nerve hypoplasia, or ONH.
In the remaining 30 patients, the optic nerve was not known to be involved, and the lesions were considered secondary.
In all 5 of the patients with MR abnormalities, increased signal was seen in the affected optic nerves on STIR sequences, while only 2 showed associated enhancement of the optic nerves.
PION is a rare condition in which there is infarction of the posterior portion of the optic nerve either following a hypotensive episode occurring intraoperatively or during a critical illness, when it is usually bilateral, or occurring spontaneously in the presence of atheromatous vascular disease or giant cell arteritis, when it typically affects just one eye.
Occasionally a physician will resort to using chemotherapy or powerful immunesuppressing medications to slow down inflammation of the optic nerves.
Since this bundle, called the optic nerve, is more accessible than are nerves inside the skull or spine, scientists have long used it as a model to investigate why other damaged nerves don't regenerate.
Unfortunately, by the time symptoms begin to surface, permanent damage to the optic nerve and vision loss have already taken root, highlighting the critical importance of early detection and treatment.
Doctors need to look at the optic nerve to see whether there are any changes suspicious for glaucoma.
Endoscopic sinus surgery in patients who have an Onodi cell (sphenoethmoid cell) carries a high risk for optic nerve injury.
Boiled down to its most basic, glaucoma is the result of damage to the optic nerve.