Congenital Cataracts
Cataract: Opacity of the lens of the eye, which occurs when fluid gathers between the lens fibres. The refractive index alters and causes light scatter with resultant blurred vision.
What Causes Congenital Cataracts?
Congenital cataracts may be unilateral or bilateral. They can be classified by morphology, presumed or defined genetic cause, presence of specific metabolic disorders, or associated ocular anomalies or systemic findings.
A unilateral cataract (in one eye only) usually has no known etiology. In some cases it can be linked with other conditions in the eye, eye trauma, or a baby being affected by an infection whilst developing in the womb.
Bilateral cataracts (in both eyes) often run in families which a baby might inherit. Up to 23% of congenital cataracts are inherited. They can also be linked with other conditions or infections, such as rubella, when the baby was growing in the womb. Medical conditions that affect the baby’s metabolism can also cause congenital cataracts
Cataracts clouding the eye's natural lens usually are associated with aging processes. But congenital cataracts occur in newborn babies for many reasons that can include inherited tendencies, infection, metabolic problems, diabetes, trauma, inflammation or drug reactions. As an example, tetracycline antibiotics used to treat infections in pregnant women have been shown to cause cataracts in newborn babies. Congenital cataracts also can occur when, during pregnancy, the mother develops infections such as measles or rubella (the most common cause), rubeola, chicken pox, herpes simplex, influenza, EpsteinBarr virus, syphilis and toxoplasmosis. Older babies and children also can be diagnosed with cataracts, known as pediatric cataracts, for similar reasons. However, trauma associated with events such as a blow to the eye is the underlying cause in 40 percent of cases of cataracts in older children. Also, in 33 percent of cases of pediatric cataracts, children were born with congenital cataracts that may initially have been overlooked.** In inherited and other forms of congenital cataracts, abnormalities may occur in the formation of proteins essential for maintaining transparency of the eye's natural lens.
Types Of Congenital Cataracts
- Anterior polar cataracts are well defined, located in the front part of the eye's lens and thought to be commonly associated with inherited traits. These types of cataracts often are considered too small to require surgical intervention.
- Posterior polar cataracts also are well defined, but appear in the back portion of the eye's lens.