Definition

Nystagmus is a type of involuntary movement of the eyes. The movement varies between slow and fast and usually involves both eyes.

Different types of nystagmus are:

• Horizontal—side-to-side
• Vertical—up and down
• Rotatory—circular
• Infantile—tends to develop between 6 weeks and 3 months of age
• Acquired—occurs later in life

Causes

The direct cause of nystagmus is instability in the motor system that controls the eyes. In some cases, the cause of nystagmus is unknown.

Risk Factors

Factors that may increase your chance of nystagmus include:

• Genetics
• A family member with nystagmus
• Poor development of eye control that may be caused by an eye disease or visual problem during infancy, such as bilateral optic nerve hypoplasia or congenital cataracts
• Lack of pigmentation— albinism
• Eye disorders, such as optic nerve degeneration or severe astigmatism or severe nearsightedness
• Health conditions, such as Meniere’s disease which involves balance problems, multiple sclerosis, spasmus nutans, or stroke
• Injury to the head or involving the body’s motor system
• Use of certain medications, such as lithium or antiseizure medications
• Alcohol abuse or drug use
• Inner ear problems, such as infections, irritation, benign paroxysmal positional vertigo, some brain tumors
• Thiamine or vitamin B12 deficiency
• Health condition that can also affects the brain

Symptoms

Nystagmus may cause:

• Sensitivity to light
• Difficulty seeing in darkness
• Vision problems
• Head held in a turned position
• Oscillopsia—feeling that the world is shaking or moving
• Vertigo

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done. If nystagmus seems to be present, you may need:

• A full exam with an eye specialist called an ophthalmologist
• An ear exam, including a hearing test
• Exam with a neurologist or other medical specialist

Tests may include the following:

• Visual exam of the inside of the eye with an ophthalmoscope
• Vision testing
• Eye movement recordings

Imaging tests may include:

• CT scan
• MRI scan

The ophthalmologist will also look for other eye problems that may be related to the nystagmus, such as strabismus, cataracts, or abnormality of the optic nerves or retina.

The ear specialist will look for signs of ear infection, and for worsening of the nystagmus with head positions.

Treatment

Talk with your doctor about the best treatment plan for you. Removal of the cause of nystagmus can sometimes eliminate the problem, for example discontinuing a medication or stopping alcohol or drug use. However, nystagmus often is a permanent condition that can only be reduced and not eliminated. Treatment options to reduce nystagmus and improve vision include the following:

• Prisms, tints, eyeglasses, or contact lenses
• Adopting a particular angle of vision where the nystagmus is reduced, such as holding the head in a certain position
• Vibratory stimulation of the face and neck
• Certain medications for certain types of nystagmus, including botox injections to relax the eye muscles, muscle relaxants, and certain anti-seizure medications
• Surgery on the eye muscles

Low-vision aids can often help improve vision. They may include large print or high contrast materials, good lighting, and magnifying devices.

Prevention

There are no current guidelines to prevent nystagmus.

Eye Smart—American Academpy of Ophthalmology http://www.eyesmart.org

Health Canada http://www.hc-sc.gc.ca

General information about nystagmus. American Nystagmus Network website. Available at:
http://www.nystagmus.org/aboutn.html
Accessed February 18, 2013.

Hertle RW. Understanding and treatment of infantile nystagmus syndrome. Presentation at the 4th Biennial Conference of the American Nystagmus Network, Los Angeles, CA. July 8-10, 2005. American Nystagmus Network website. Available at:
http://www.nystagmus.org/doc/conf2005/hertle_ANN.pdf
Accessed February 18, 2013.

Nystagmus. American Academy of Ophthalmology Eye Smart website. Available at:
http://www.geteyesmart.org/eyesmart/diseases/nystagmus.cfm
Accessed February 18, 2013.

Maybodi M. Understanding nystagmus: diagnosis, related disorders, treatment, and research. Presentation at the 3rd Biennial Conference of the American Nystagmus Network, Baltimore, MD. July 11-13, 2003. Available at:
http://www.nystagmus.org/doc/conf2003/KEYNOTE.pdf
Accessed February 18, 2013.