A cataract is a clouding of the eye’s natural lens, which normally works to focus light and produce clear images. While often associated with aging, cataracts can also occur in newborns, a condition known as congenital cataract. This cloudy lens can interfere with a baby’s developing vision.
Understanding Newborn Cataracts
A congenital cataract is an opacity within the lens, making it difficult for light to pass through and reach the retina. This clouding can range from a small, subtle spot to a dense, widespread opacity that significantly obstructs vision. The condition is relatively uncommon, affecting approximately 1 to 6 out of every 10,000 live births.
The cataract can be present in one eye (unilateral) or both eyes (bilateral). When a cataract is visually significant, meaning it impacts vision, it can hinder the normal development of the visual pathways in the brain. This interference is important for long-term visual health.
Causes of Newborn Cataracts
Newborn cataracts can arise from a variety of factors, and often, the exact cause is unknown. Genetic factors are a common reason, leading to abnormal lens development during pregnancy. Some babies inherit a defective gene, and conditions like Down syndrome can also increase the risk.
Infections contracted by the mother during pregnancy are another cause. These include rubella, toxoplasmosis, herpes simplex virus, cytomegalovirus, chickenpox, and syphilis, often referred to as TORCH infections. Rubella, if contracted in the first trimester, carries a higher risk.
Other, less common causes include metabolic disorders like galactosemia, where the body cannot process a certain sugar, or hypocalcemia. Trauma to the eye during pregnancy, though rare, can injure the baby’s eye and lead to cataracts. Premature birth is a risk factor because eyes may not be fully developed, increasing the chance of abnormal lens formation.
Detecting and Diagnosing Cataracts
Newborn cataracts are often identified through routine eye screenings before a baby leaves the hospital. The primary screening method is the red reflex test, where a provider shines a light into the baby’s eyes to observe the reflection from the retina. A normal red reflex appears as a symmetrical reddish-orange glow in both pupils.
An abnormal red reflex, such as a dull, absent, or white reflection, or the presence of dark spots, can signal an opacity like a cataract. Parents might notice signs at home, such as a white or gray pupil, unusual eye movements like nystagmus (involuntary rhythmic eye movements), or a lack of awareness of their surroundings. If any of these signs are observed, a prompt referral to a pediatric ophthalmologist is recommended.
The ophthalmologist will perform a thorough eye examination, which may include using a lighted magnifying device to view the lens. Additional tests, such as blood tests, X-rays, or CT scans, may check for underlying infections or genetic conditions associated with the cataract.
Treatment and Early Intervention
For visually significant congenital cataracts, surgical removal of the cloudy lens is the primary treatment. This procedure, often an extracapsular cataract extraction, removes the opaque lens material. Pediatric eyes are prone to posterior capsular opacification. A primary posterior capsulotomy and anterior vitrectomy are often performed during initial surgery to minimize subsequent interventions.
Early intervention is important for visual development, as delaying treatment can lead to permanent vision impairment, particularly amblyopia, or “lazy eye”. Unilateral congenital cataracts are recommended to be removed by six weeks of age and bilateral cataracts by ten weeks of age to limit deprivation amblyopia. Research indicates early surgery (before eight weeks for unilateral and before twelve weeks for bilateral cases) significantly reduces amblyopia risk.
Following surgery, visual rehabilitation is continuous. Since the natural lens is removed, the eye cannot focus light properly. Infants will need optical correction, often with contact lenses or aphakic glasses, to focus images. Patching therapy, where the stronger eye is covered, is often used, especially for unilateral cataracts, to encourage the weaker eye to develop better vision.
Life After Cataract Treatment
Children who undergo cataract treatment require ongoing follow-up care with a pediatric ophthalmologist. Long-term monitoring is important to manage potential complications and support visual development. Regular appointments help ensure the child’s vision develops well and adjust optical corrections as the child grows.
One common concern after surgery is secondary cataracts, also known as posterior capsular opacification, where the membrane behind the implanted lens can become cloudy. Another potential complication is glaucoma, characterized by increased pressure inside the eye that can damage the optic nerve. Studies show a higher incidence of glaucoma in children who underwent cataract surgery at a young age.
Visual rehabilitation extends beyond surgery and optical correction, focusing on encouraging the brain to use vision from the treated eye. This may involve continued patching therapy and other visual stimulation techniques to promote the best long-term visual outcomes. Consistent follow-up and adherence to rehabilitation strategies can maximize a child’s visual potential.