(See also Cataracts Cataract A cataract is a congenital or degenerative opacity of the lens. The main symptom is gradual, painless vision blurring. Diagnosis is by ophthalmoscopy and slit-lamp examination. Treatment is... read more in adults.)
Congenital cataracts may be sporadic, or they may be caused by chromosomal anomalies Overview of Chromosomal Anomalies Chromosomal anomalies cause various disorders. Anomalies that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect sex chromosomes... read more , metabolic disease (eg, galactosemia Galactosemia Galactosemia is a carbohydrate metabolism disorder caused by inherited deficiencies in enzymes that convert galactose to glucose. Symptoms and signs include hepatic and renal dysfunction, cognitive... read more ), intrauterine infection (eg, rubella Rubella (See also Congenital Rubella.) Rubella is a contagious viral infection that may cause adenopathy, rash, and sometimes constitutional symptoms, which are usually mild and brief. Infection during... read more ), or other maternal disease during pregnancy. Congenital cataracts may also be an isolated familial anomaly that is commonly autosomal dominantly inherited Autosomal Dominant Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele)... read more .
Cataracts may be located in the center of the lens (nuclear), or they may involve the lens material underneath the anterior or posterior lens capsule (subcapsular or cortical). They may be unilateral or bilateral. They may not be noticed unless the red reflex is checked or unless ophthalmoscopy is done at birth. As with other cataracts, the lens opacity obscures vision. Cataracts may obscure the view of the optic disc and vessels and should always be evaluated by an ophthalmologist.
Cataracts are removed by aspirating them through a small incision. In many children, an intraocular lens may be implanted. Postoperative visual correction with eyeglasses, contact lenses, or both is usually required to achieve the best outcome.
After a unilateral cataract is removed, the quality of the image in the treated eye is inferior to that of the other eye (assuming the other eye is normal). Because the better eye is preferred, the brain suppresses the poorer-quality image, and amblyopia Amblyopia Amblyopia is functional reduction in visual acuity of an eye caused by disuse during visual development. Severe loss of vision can occur in the affected eye if amblyopia is not detected and... read more develops. Thus, effective amblyopia therapy Treatment Amblyopia is functional reduction in visual acuity of an eye caused by disuse during visual development. Severe loss of vision can occur in the affected eye if amblyopia is not detected and... read more is necessary for the treated eye to develop normal sight. Some children are unable to attain good visual acuity because of accompanying structural defects. In contrast, children with bilateral cataract removal in which image quality is similar in both eyes more frequently develop equal vision in both eyes.
Some cataracts are partial (posterior lenticonus) and opacify during the first 10 years of life. Eyes with partial cataracts will have a better visual outcome.