Optic Chiasm | Health Encyclopedia: Optic Chiasm

Optic Chiasm: From 1 Different Sources

(optic commissure) the X-shaped structure formed by the two optic nerves, which pass backwards from the eyeballs to meet in the midline beneath the brain, near the pituitary gland (see illustration). Nerve fibres from the nasal side of the retina of each eye cross over to join fibres from the lateral side of the retina of the opposite eye. The optic tracts resulting from the junction pass backwards to the occipital lobes.

Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Optic Atrophy

A deterioration in the ?bres of the optic nerve (see EYE) resulting in partial or complete loss of vision. It may be caused by damage to the nerve from in?ammation or injury, or the atrophy may be secondary to disease in the eye.... optic atrophy

Optic Disc

Otherwise known as the blind spot of the EYE, the disc is the beginning of the optic nerve – the point where nerve ?bres from the retina’s rods and cones (the light- and colour-sensitive cells) leave the eyeball.... optic disc

Optic Neuritis

In?ammation of the optic nerve (see EYE) which may result in sudden loss of part of a person’s vision. It is usually accompanied by pain and tenderness on touch. The cause is uncertain, although in some cases it may be a prcursor of MULTIPLE SCLEROSIS (MS): CORTICOSTEROIDS may help by improving the loss of visual acuity, but seems not to check the long-term in?ammatory activity.... optic neuritis

Chiasma

This is an X-shaped crossing. The optic chiasma is where the nerve ?bres from the nasal half of each retina cross over the mid line to join the optic tract from the other side.... chiasma

Optic

Concerned with the EYE or vision.... optic

Optic Chiasma

This is formed by a crossing-over of the two optic nerves (see EYE) which run from the back of the eyeballs to meet in the mid line beneath the brain. Nerve ?bres from the nasal part of the retina cross to link up with ?bres from the outer part of the retina of the opposite eye. The linked nerves form two separate optic tracts which travel back to the occipital lobes of the brain.... optic chiasma

Leber’s Optic Atrophy

a rare hereditary disorder, usually affecting young males, that is characterized by loss of central vision due to neuroretinal degeneration. Visual loss in one eye is rapid and usually followed by loss in the second eye. [T. Leber]... leber’s optic atrophy