Cataracts

A cataract is any opacity of the lens (Fig. 620-1). Some are clinically unimportant; others significantly affect visual function. The incidence of infantile cataracts is approximately 2-13/10,000 live births. An epidemiologic study of infantile cataracts published in 2003 suggests that approximately 60% of cataracts are an isolated defect; 22% are part of a syndrome; and the remainder is associated with other unrelated major birth defects. Cataracts are more common in low birthweight infants. Infants at or below 2,500 g have a 3- to 4-fold increased odds of developing infantile cataracts. Some cataracts are associated with other ocular or systemic disease.

Figure 620-1 Leukocoria secondary to cataract.

Differential Diagnosis

The differential diagnosis of cataracts in infants and children includes a wide range of developmental disorders, infectious and inflammatory processes, metabolic diseases, and toxic and traumatic insults (Table 620-1). Cataracts may also develop secondary to intraocular processes, such as retinopathy of prematurity, persistent hyperplastic primary vitreous, retinal detachment, retinitis pigmentosa, and uveitis. A portion of cataracts in children are inherited (Fig. 620-2).

Table 620-1 DIFFERENTIAL DIAGNOSIS OF CATARACTS

DEVELOPMENTAL VARIANTS

Prematurity (Y-suture vacuoles) with or without retinopathy of prematurity

GENETIC DISORDERS

Simple Mendelian Inheritance

Autosomal dominant (most common)

Autosomal recessive

X-linked

Major Chromosomal Defects

Trisomy disorders (13, 18, 21)

Turner syndrome (45X)

Deletion syndromes (11p13, 18p, 18q)

Duplication syndromes (3q, 20p, 10q)

Multisystem Genetic Disorders

Alport syndrome (hearing loss, renal disease)

Alström syndrome (nerve deafness, diabetes mellitus)

Apert disease (craniosynostosis, syndactyly)

Cockayne syndrome (premature senility, skin photosensitivity)

Conradi disease (chondrodysplasia punctata)

Crouzon disease (dysostosis craniofacialis)

Hallermann-Streiff syndrome (microphthalmia, small pinched nose, skin atrophy, and hypotrichosis)

Hypohidrotic ectodermal dysplasia (anomalous dentition, hypohidrosis, hypotrichosis)

Ichthyosis (keratinizing disorder with thick, scaly skin)

Incontinentia pigmenti (dental anomalies, mental retardation, cutaneous lesions)

Lowe syndrome (oculocerebrorenal syndrome: hypotonia, renal disease)

Marfan syndrome

Meckel-Gruber syndrome (renal dysplasia, encephalocele)

Myotonic dystrophy

Nail-patella syndrome (renal dysfunction, dysplastic nails, hypoplastic patella)

Marinesco-Sjögren syndrome (cerebellar ataxia, hypotonia)

Nevoid basal cell carcinoma syndrome (autosomal dominant, basal cell carcinoma erupts in childhood)

Peters anomaly (corneal opacifications with iris-corneal dysgenesis)

Reiger syndrome (iris dysplasia, myotonic dystrophy)

Rothmund-Thomson syndrome (poikiloderma: skin atrophy)

Rubinstein-Taybi syndrome (broad great toe, mental retardation)

Smith-Lemli-Opitz syndrome (toe syndactyly, hypospadias, mental retardation)

Sotos syndrome (cerebral gigantism)

Spondyloepiphyseal dysplasia (dwarfism, short trunk)

Werner syndrome (premature aging in 2nd decade of life)

Inborn Errors of Metabolism

Abetalipoproteinemia (absent chylomicrons, retinal degeneration)

Fabry disease (α-galactosidase A deficiency)

Galactokinase deficiency

Galactosemia (galactose-1-phosphate uridyl transferase deficiency)

Homocystinemia (subluxation of lens, mental retardation)

Mannosidosis (acid α-mannosidase deficiency)

Niemann-Pick disease (sphingomyelinase deficiency)

Refsum disease (phytanic acid α-hydrolase deficiency)

Wilson disease (accumulation of copper leads to cirrhosis and neurologic symptoms)

ENDOCRINOPATHIES

Hypocalcemia (hypoparathyroidism)

Hypoglycemia

Diabetes mellitus

CONGENITAL INFECTIONS

Toxoplasmosis

Cytomegalovirus infection

Syphilis

Rubella

Perinatal herpes simplex infection

Measles (rubeola)

Poliomyelitis

Influenza

Varicella-zoster

OCULAR ANOMALIES

Microphthalmia

Coloboma

Aniridia

Mesodermal dysgenesis

Persistent pupillary membrane

Posterior lenticonus

Persistent hyperplastic primary vitreous

Primitive hyaloid vascular system

MISCELLANEOUS DISORDERS

Atopic dermatitis

Drugs (corticosteroids)

Radiation

Trauma

IDIOPATHIC

Figure 620-2 Central lamellar cataract.