Optic Nerve Atrophy

The optic nerve carries images of what we see coded as electrical impulses, from the retina to our brain. The optic nerve is like a cable of more than a million tiny electrical wires, or nerve fibers each carrying a part of the visual information. If these nerve fibers become damaged, the brain doesn't get all the vision information and our sight becomes blurred.

Optic nerve atrophy can be defined as damage to the optic nerve resulting in a degeneration or destruction of the optic nerve. Optic atrophy may also be referred to as optic nerve head pallor because of the pale appearance of the optic nerve head as seen at the back of the eye.

• Blurred vision
• Decrease in visual function such as a decrease in sharpness and clarity of vision (visual acuity) or decreases in side (peripheral) vision. Color vision and contrast sensitivity can also be affected.
• Poor constriction of the pupil in light
• Decreased brightness in one eye relative to the other
• Change in the optic disc

The symptoms described above may not necessarily mean that you have optic atrophy. However, if you experience one or more of these symptoms, contact your eye doctor for a complete exam.

Most commonly, optic atrophy simply occurs without a known or proven cause.

Possible causes of optic atrophy can range from trauma to systemic disorders. Some possible causes of optic atrophy include:

• Optic neuritis. Optic neuritis is an inflammation of the optic nerve. It may be associated with eye pain worsened by eye movement. It is more common in young to middle-aged women. Some patients with optic neuritis may develop multiple sclerosis later on in life.
• Leber's hereditary optic neuropathy. This is a disease of young men (late teens, early 20s), characterized by an onset over a few weeks of painless, severe, central visual loss in one eye, followed weeks or months later by the same process in the other eye. At first the optic disc may be slightly swollen, but eventually there is optic atrophy. The visual loss is generally permanent. This condition is hereditary. If a patient knows that Leber's runs in the family, genetic counseling should be considered.
• Toxic optic neuropathy. Nutritional deficiencies and poisons can be associated with gradual vision loss and optic atrophy, or with sudden vision loss and optic disc swelling. Toxic and nutritional optic neuropathies are uncommon in the United States, but took on epidemic proportions in Cuba in 1992-1993. The most common toxic optic neuropathy is known as tobacco-alcohol amblyopia, thought to be caused by exposure to cyanide from tobacco smoking, and by low levels of vitamin B12 because of poor nutrition and poor absorption associated with drinking alcohol. Other possible toxins included ethambutol, methyl alcohol (moonshine), ethylene glycol (antifreeze), cyanide, lead, and carbon monoxide. Certain medications have also been implicated. Nutritional optic neuropathy may be caused by deficiencies of protein, or of the B vitamins and folate, associated with starvation, malabsorption, or alcoholism.
• Glaucoma. Glaucoma may be caused by an increase of pressure inside the eye. This increased pressure may eventually affect the optic nerve if left untreated.
• Compressive optic neuropathy. This is the result of a tumor or other lesion putting pressure on the optic nerve. Another possible cause is enlargement of muscles involved in eye movement seen in hyperthyroidism (Graves' disease).
• Retinitis pigmentosa. This is a hereditary ocular disorder.
• Syphilis. Left untreated, this disease may result in optic atrophy.

Unfortunately, there is no effective treatment for optic atrophy. Once the nerve fibers in the optic nerve are lost they never heal or grow back. Therefore, the best defense is an early diagnosis because if the cause can be found and corrected, further damage can be prevented.

Self Help:

Since we consider most eye conditions to be a reflection of the health of the whole body, lifestyle choices and diet can play a major factor in getting and maintaining good vision. Below are some recommendations: