Optic Nerve Disorders
What are Optic Nerve Disorders?
The optic nerve is a bundle of more than 1 million nerve fibers. Nerve signals travel along the optic nerve from each eye and send visual information to the brain.
Damage along the optic nerve pathway causes specific patterns of vision loss. The three types of vision loss caused by optic nerve disorders are:
- One eye or one optic nerve is damaged; vision loss occurs on the affected side
- The optic chiasm, the space behind the eyes where the optic nerves meet, is damaged; vision in the outer part of both eyes is lost
- If the visual pathways from the optic chiasm to the visual cortex (the portion of the brain that comprehends visual information) are damaged, one side of the visual field is lost in both eyes; for example, damage on the right side of the brain causes the loss of the left visual field in both eyes
There are many different types of disorders that can affect the optic nerve, including:
- Coloboma of optic nerve
- Idiopathic intracranial hypertension
- Neuromyelitis optica
- Optic nerve atrophy
- Optic nerve drusen
- Optic nerve pit
- Optic neuritis
- Septo-optic dysplasia
- Toxic amblyopia (nutritional amblyopia)
Optic Nerve Disorders Symptoms
Depending on the condition, symptoms may include:
- Blurred vision
- Eye pain, sometimes worsened by eye movement
- Eye redness
- Flashing lights
- Halos around lights
- Loss of color vision
- Nausea and vomiting
- Severe headache
- Vision loss
- Visual field loss
Optic Nerve Disorders Treatments
Treatments and procedures for optic nerve disorders may include:
- Abscess drainage
- Antibiotics to control infection
- Avoidance of alcohol
- Control of blood pressure, diabetes, weight, and other risk factors
- Low vision aids, including magnifiers, large-print devices, and talking watches
- Optic nerve decompression – a surgical procedure that removes a portion of the bony canal (tunnel) which houses the optic nerve
- Vitamin supplements
How common are optic nerve disorders?
The rate of optic nerve disorders varies with each form of the condition. Glaucoma is the most common optic nerve disorder and occurs in more than 3 million people each year in the U.S.
Who gets optic nerve disorders?
Optic nerve disorders may be caused by developmental factors, such as genetic or abnormal development, or by acquired factors, such as trauma or disease.
How are optic nerve disorders diagnosed?
Tests for optic nerve disorders may include:
- Eye exams
- Ophthalmoscopy (an examination of the back of the eye)
- Imaging tests, such as magnetic resonance imaging (MRI)