Cataracts

What is a cataract?

A cataract is a clouding or opaque area over the lens of the eye - an area that is normally transparent. As this thickening occurs, it prevents light rays from passing through the lens and focusing on the retina - the light sensitive tissue lining located in the back of the eye. With some cataracts, this clouding is caused when some of the protein which makes up the lens begins to clump together and interferes with vision. Cataracts occur in about 0.4 percent of children. They can affect either one eye (unilateral) or both eyes (bilateral).

The word "cataract" literally means "waterfall." For persons with an advanced cataract that covers a large portion of the eye lens, vision can be described as trying to see through a waterfall.

Some cataracts are small and do not cause any visual symptoms. However, other, more progressive cataracts can cause visual problems in children. Cataracts in children are uncommon.

What causes cataracts?

A child may be born with the disease (congenital), or it may develop later in life (acquired). Possible causes of cataracts include the following:

• Trauma
• Diabetes
• Poisoning
• Steroid use
• Other childhood diseases such as rheumatoid arthritis
• Complications from other eye diseases, such as glaucoma

The majority of congenital cataracts (those present at birth) are present in children who also have other eye problems or other health problems. In approximately 25 percent of children born with congenital cataracts, the condition is due to a genetic cause such as a metabolic disorder (caused by an inherited enzyme deficiency) or a chromosome abnormality (i.e., Down syndrome).

What are the symptoms of cataracts?

The following are the most common symptoms of cataracts. However, each child may experience symptoms differently. Symptoms may include:

• White pupil upon flashlight examination
• Misaligned eyes
• Involuntary rhythmic movements of the eyes back and forth, up and down, around or mixed (nystagmus)
• Cloudy or blurry vision
• Decreased vision
• Lights appear too bright and/or present a glare or a surrounding halo

The symptoms of cataracts may resemble other eye conditions. Always consult your child's physician for a diagnosis.

What are the different types of cataracts?

According to the National Eye Institute, part of the National Institutes of Health, cataract types are subdivided accordingly:

• Congenital cataracts - Some babies are born with cataracts or develop them in childhood, often in both eyes. Some congenital cataracts do not affect vision, but others do and need to be removed.
• Secondary cataracts - Secondary cataracts develop primarily as a result of another disease occurrence in the body (i.e., juvenile diabetes or another ocular problem). Secondary cataract development has also been linked to some medications (i.e., steroids).
• Traumatic cataracts - Eye(s) that have sustained an injury may develop a traumatic cataract either immediately following the incident, or several years later.
• Age-related cataracts - The majority of cataracts are related to aging. 

How are cataracts diagnosed?

In addition to a complete medical history and eye examination of your child, diagnostic procedures for cataracts may include:

• Visual acuity test - The common eye chart test, which measures vision ability at various distances.
• Pupil dilation - The pupil is widened with eyedrops to allow a close-up examination of the eye's retina and lens.

In addition, other tests may also be performed to help learn more about the health and structure of your child's eyes.

Treatment for cataracts:

Specific treatment for cataracts will be determined by your child's physician based on:

• Your child's age, overall health and medical history
• Extent of the disease
• Your child's tolerance for specific medications, procedures or therapies
• Expectations for the course of the disease
• Your opinion or preference

Treatment is tailored to the child and the type of cataract he/she has. In some cases, vision loss caused by a cataract may be aided by eyeglasses or contact lenses. However, surgical removal of cataracts is often recommended in infants and children.