Cataract

What is a cataract?

A cataract is the clouding of the eye’s normally clear lens.  The lens is located directly behind the iris (the colored part of the eye).   The lens’ job is to help focus the light on the retina (the light sensitive tissue on the back of the eye).  A cloudy lens prevents light rays from reaching the retina and results in hazy, or blurry, vision.  The degree of visual impairment caused by a cataract varies and depends on how much of the lens is affected by the cataract.

What causes cataracts in children?

Although most cataracts occur in adults as part of the aging process, infants and children can also be affected.  Occasionally infants are even born with a cataract.  Although infant cataracts may be inherited or occur as part of certain infections, such as German measles (rubella) it is usually impossible to determine the exact cause.  Certain blood and urine tests may be performed to evaluate some of the known causes; most often they are negative.

A cataract may develop later in childhood often as a result of eye injury or a disease process involving other parts of the body.  Other causes include abnormal lens growth or the late appearance of inherited cataracts.

How are cataracts treated?

Some childhood cataracts that involve only part of the lens may not interfere with vision.  These small cataracts usually do not require treatment but should be observed periodically.  Moderate size cataracts that do interfere with vision may require treatment with glasses with treatment for amblyopia (“lazy” eye).  Larger cataracts which severely affect the vision require immediate surgery.

Using very special microsurgical techniques an ophthalmologist removes the entire lens.  All cataract operations require incisions into the eye.  In children, this surgery is performed under general anesthesia.  LASERS CANNOT REMOVE CATARACTS!

How is vision corrected after surgery?

Once the cloudy lens is removed, the child will need a substitute lens to focus images on the retina.   This can be done with glasses, contacts lenses or intraocular lenses.  The decision on regarding the type of visual correction is personalized for each case.  It is a decision that you and your ophthalmologist will make together.  REGARDLESS OF THE METHOD THE CHILD WILL ALWAYS NEED BIFOCAL GLASSES TO SEE NEAR OBJECTS CLEARLY.

Glasses work well for children who have had cataracts removed from both eyes.  They cannot be used if the cataract has been removed from one eye only, due to the difference in magnification that would result between to two eyes.   The child would see one magnified image (on the side that had the cataract surgery) and one normal image, resulting in double vision.   The child’s brain would correct for this by “turning off” (suppressing) the image from the operated eye.  This results in amblyopia, or “lazy” eye. (See below.)  

Contact lenses are used when the surgery is performed in one or two eyes.  Usually, special high powered lenses made of silicone are used.   The exact type of lens used for each patient is determined on an individual basis.  This fit takes into account the shape, and length of the eye as well as the patient, of parent’s dexterity.  Since an infant’s eye grows rapidly, frequent lens changes may be necessary.

One of the newest ways of correcting the focusing power in infants with cataracts is by using an artificial implant in the same way that they are used for adults.  However unlike adults, in children it is often difficult to predict what power intraocular lens will be needed as the child’s eye is still growing.  The growth of the eye will affect the power needed for clear focusing.  If an intraocular lens is placed, the surgeon(s) will pick a power based on the length and curvature of the eye(s) as well as by using their expertise in this field and best judgment.    If an intraocular lens is placed, depending on the condition of the eye(s) and child’s age, it could require removal in the future because of lens power modifications, problems with scarring, displacement, or inflammation.  All of the above mentioned treatments as well as glasses, eye patches, eye drops, and additional surgeries may be needed.

Amblyopia

Poor vision resulting from amblyopia or “lazy” eye can be caused by a cataract.  While the visual system is developing, the brain must receive clear images to both eyes.  If this does not occur, the visual part of the brain for that eye will not develop properly.  For this reason, when a cataract develops in infancy surgery should be performed as soon as vision is threatened. 

When amblyopia is present, cataract removal is only the first step in treatment.  Proper optical correction is necessary and intensive patching regimens will be likely.  Even with prompt and aggressive treatment, some children develop only partial visual recovery.

Please see our additional section on cataract surgery for more information.