CATARACTS COMMON CAUSE OF BLINDNESS IN CHILDREN
By David Mallory, M.D.

    A recent study in England showed cataracts to be the most common cause of partial sight or blindness in 10-year-olds. In this country 10 to 40 percent of blindness in infants is caused by cataracts.

    The introduction of ultrasound to remove cataracts through a one-eighth-inch incision revolutionized the surgical treatment of cataracts in both children and adults.

    Prior to this, the surgical treatment of cataracts in children was a rather primitive disruption of the lens with a needle so that the lens would self-absorb. Unfortunately a severe and unpredictable amount of scarring resulted from this procedure and a second operation was necessary.

    Until the introduction of phacoemulsification (the removal of a cataract with ultrasound), the status of cataract surgery in children had not really changed much from when the needling procedure had been first used by the Persians 1,300 years ago.

    Infection of the mother with rubella or German measles in the first three months of her pregnancy remains the leading known cause of infant or congenital cataracts, despite immunizations against the disease. Heredity is the second most common cause followed by drug abuse.

    There are special considerations when dealing with cataracts in children.

    Unlike adult cataracts, a congenital cataract (one that develops within three months of birth) may not progress but remain the same throughout the person's life.

    If the cataract is small and vision is fairly good, surgery is not needed. The pupil may be dilated so that light can get in around the cataract to prevent amblyopia (a lazy eye).

    Early detection of larger cataracts in the newborn which severely interfere with vision is extremely important. Newborns with cataracts who are operated on after eight weeks of age not only are much more likely to have an irreversible lazy eye but even lag in psychological development.

    Infants with cataracts in both eyes operated on after 10-12 weeks of age are likely to have poor vision and to develop a wandering, jerky movement of the eyes called nystagmus.

    Blindness due to cataracts in adults is totally treatable and avoidable at any time, but in children it is different. If a cataract deprives light stimulation to the eye long enough, the visual system of the brain does not develop properly. The result may be a lazy or poorly seeing eye even if the cataract is removed.

    Infants' eyes should be examined for cataracts by the pediatrician or family practitioner.

    Regular exams at your eye doctor's office should begin when a child turns 3 years of age, with regular exams thereafter.

David Mallory, M.D. is a cataract, intraocular lens, and laser surgery specialist at the Southwest Eye Clinic.