What is congenital cataract and why does it occur?

If you are told that your newborn baby has a congenital cataract, this means that the eye’s natural lens is cloudy instead of clear. Vision could be hampered to the extent that cataract surgery may be required for removal of your child’s natural lens (that is, the cataract).

In about 0.4 percent of all births, congenital cataracts are found or soon develop. Not all congenital cataracts require surgical removal, but many do. Cataracts that cloud only the peripheral portion of the lens may not need removal, because central vision remains unimpeded. Very small cataracts, too, may be considered too insignificant to require surgery.

What Causes 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, cytomegalovirus, herpes simplex, herpes zoster, poliomyelitis, influenza, Epstein-Barr 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.
• Nuclear cataracts appear in the central part of the lens and are a very common form of congenital cataracts.
• Cerulean cataracts usually are found in both eyes of infants and are distinguished by small, bluish dots in the lens. Typically, this type of cataract does not cause vision problems. Cerulean cataracts appear to be associated with inherited tendencies.

When Should My Child Have Cataract Surgery?

Opinions vary about when cataract surgery should be performed on an infant, because of concerns about complications such as development of high eye pressure that could lead to secondary glaucoma. High IOP can occur if cataract surgery damages the fluid outflow structure (trabecular meshwork) inside the eye. Also, the use of anesthesia for surgery involving very young infants can be cause for safety concerns.

On the other hand, cataract surgery may need to be performed as soon as possible to ensure that vision is clear enough to allow normal development of your baby’s vision system. Some experts say the optimal time to intervene and remove a visually significant congenital cataract from an infant’s eye is between the ages of 6 weeks and 3 months.

If your baby has a congenital cataract, discuss any concerns you have about timing of cataract surgery with your eye surgeon.

Reference:

https://www.allaboutvision.com/conditions/congenital-cataracts.htm

https://www.rnib.org.uk/eye-health-eye-conditions-z-eye-conditions/congenital-cataracts