A congenital cataract is a clouding of the eye’s lens that is present at birth or develops within an infant’s first few months. The lens, a normally clear structure, focuses light onto the retina to create sharp images. When a cataract forms, this lens becomes opaque, obstructing light and leading to impaired vision. This condition can occur in one eye (unilateral) or both (bilateral).
Unlike cataracts in older adults, congenital cataracts interfere with vision during a sensitive period of development. The brain and eyes must work together for sight to develop correctly, and if a cataract blocks clear images from reaching the brain, this process can be disrupted. Early identification and management are necessary for a child’s visual future.
Causes of Congenital Cataracts
The origins of congenital cataracts are varied, with genetic factors being a primary contributor. In about one-third of cases, the condition is inherited, often following a pattern where an altered gene from one parent is enough to cause the disorder. These genetic mutations interfere with the normal formation of proteins that make up the lens.
Maternal health during pregnancy can also play a part. Intrauterine infections that pass from mother to fetus are a known cause, including viruses like rubella, cytomegalovirus (CMV), herpes, and toxoplasmosis.
Certain metabolic disorders are also linked to this condition. Galactosemia, a rare genetic metabolic disorder, prevents the body from breaking down the sugar galactose, and its buildup can damage the lens. The condition can also be associated with genetic syndromes, such as Down syndrome. In many cases, the specific reason for a congenital cataract cannot be identified (idiopathic).
Signs and Diagnosis
Congenital cataracts are frequently detected during the routine newborn examination. A primary screening tool is the red reflex test, which involves shining a light from an ophthalmoscope into the baby’s eyes. In a healthy eye, this light produces a reddish-orange glow, similar to the “red eye” effect in flash photography. An abnormal, absent, or white reflex can indicate an obstruction like a cataract.
Parents or caregivers may also be the first to notice signs of a vision problem. A visible white or gray cloudiness in the pupil, a condition called leukocoria, is a prominent indicator. Other symptoms can include unusual, rapid eye movements (nystagmus), or an infant not tracking faces or objects as expected.
If any of these signs are observed, a pediatrician will refer the infant to a pediatric ophthalmologist for a comprehensive evaluation. The specialist conducts a dilated eye exam to confirm the diagnosis, determine the cataract’s size and density, and check for other eye abnormalities.
Surgical Intervention
For cataracts dense enough to interfere with vision, surgery is the only effective treatment. The timing of this intervention is often urgent, particularly for significant unilateral cataracts. To prevent permanent vision loss from amblyopia, surgery is frequently recommended within the first 4 to 6 weeks of life. This early window is important for allowing the brain’s visual pathways to develop properly.
The surgical procedure, a lensectomy, involves removing the clouded lens. A pediatric ophthalmologist makes a small incision in the eye and uses specialized instruments to break up and aspirate the lens material.
Following the removal of the natural lens, a decision is made about how to restore the eye’s focusing power. One option is the implantation of a permanent, artificial intraocular lens (IOL). However, the use and timing of IOLs in very young infants can be complex due to the continued growth of the eye. The specific approach depends on the infant’s age, whether one or both eyes are affected, and the surgeon’s clinical judgment.
Post-Operative Vision Development
The removal of the cataract is the first step in a longer journey of visual rehabilitation. After surgery, the infant’s eye requires a new method to focus light, especially if an intraocular lens was not implanted. This is achieved with specially fitted infant contact lenses or, in some cases, powerful eyeglasses. Consistent use of these corrective lenses is needed to provide the brain with a clear image to process.
A primary goal of post-operative care is to prevent the development of amblyopia, or “lazy eye.” Amblyopia occurs when the brain favors the stronger eye and begins to ignore signals from the weaker eye that had the cataract. To combat this, patching therapy is often initiated. This involves placing an adhesive patch over the stronger eye for several hours each day, forcing the brain to rely on and strengthen the vision in the surgically-treated eye.
This rehabilitation process is a long-term commitment, often continuing until the child’s visual system is fully developed around age 8 to 10. Regular follow-up appointments with the ophthalmologist are necessary to monitor vision, adjust prescriptions, and manage potential complications.