Optic nerve

The optic nerve is the nerve that transmits visual information from the retina to the brain.

Role in disease

Damage to the optic nerve typically causes permanent and potentially severe loss of vision, as well as an abnormal pupillary reflex, which is diagnostically important. The type of visual field loss will depend on which portions of the optic nerve were damaged. Generally speaking:

Related Topics:
Vision - Pupillary reflex - Visual field

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• Damage before the optic chiasm affect vision in the visual field of the same side only.
• Damage in the chiasm causes loss of vision laterally in both visual fields (bitemporal hemianopia). It may occur in large pituitary adenomata.
• Damage after the chiasm causes loss of vision on one side but affecting both visual fields: the visual field affected is located on the opposite side of the lesion.

Injury to the optic nerve can be the result of congenital or inheritable problems like Leber's Hereditary Optic Neuropathy, glaucoma, trauma, toxicity, inflammation, ischemia, infection (very rarely), or compression from tumors or aneurysms. By far, the three most common injuries to the optic nerve are from glaucoma, optic neuritis (especially in those younger than 50 years of age) and anterior ischemic optic neuropathy (usually in those older than 50).

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Glaucoma is a group of diseases involving loss of retinal ganglion cells causing optic neuropathy in a pattern of peripheral vision loss, initially sparing central vision.

Related Topics:
Glaucoma - Ganglion cell - Optic neuropathy - Peripheral vision

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Optic neuritis is inflammation of the optic nerve. It is associated with a number of diseases, most notably multiple sclerosis.

Related Topics:
Optic neuritis - Multiple sclerosis

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Anterior Ischemic Optic Neuropathy is a particular type of infarct that affects patients with an anatomical predisposition and cardiovascular risk factors.

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Ophthalmologists, particularly those subspecialists who are neuro-ophthalmologists, are often best suited to diagnose and treat diseases of the optic nerve.

Related Topics:
Ophthalmologist - Neuro-ophthalmologist

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