Pediatric Ophthalmology
Edited by P. F. Gallin
Thieme Medical Publishers, Inc.
New York ©2000
20
Pediatric Cataracts
Evaluating children with cataracts is very difficult because children with cataracts are not just small adults with cataracts. They present numerous problems and challenges that involve medical, social, and surgical issues.
The care of children with cataracts begins with the first ophthalmologic examination and extends until at least 9 years of age due to the window of amblyopia. Often they develop additional ophthalmologic problems later in life. The ability to examine an infant and determine whether a lens opacity is visually significant, requiring urgent surgery, or inconsequential is an acquired skill with little room for error. Often, care of the pediatric cataract patient involves the coordination of a number of different specialists, including geneticists, pediatricians, social workers, and ophthalmologists.
Signs and Symptoms
Pediatric cataracts are often an incidental finding, especially when they are monocular. The management of pediatric cataracts varies greatly with patient age, extent of amblyopia, and significance of lens opacity. The presence of an opacity and the difficulty in diagnosis become two separate entities. Newborns are screened at birth, and any abnormality in the red reflex usually is brought to the attention of an ophthalmologist. Because newborns are examined with direct ophthalmoscopes, which constrict reactive pupils, partial and visually significant lens opacities are difficult to diagnose. Routine well baby pediatrician visits may detect a lens opacity in the red reflex. However, it is the appearance of a “funny looking eye” or different red reflexes on family photographs that can bring this to medical attention. Children with dense bilateral cataracts may presentwith nystagmus. Other findings that may prompt examination include strabismus and complaints of glare/ photophobia. Failure to perform visually oriented tasks may not be noted, especially if the opacity is in one eye and the child functions normally with the other. Children with signs of developmental delay (i.e., failure to reach normal milestones), or features of clinical syndromes associated with ocular involvement should be routinely referred for comprehensive ophthalmologic evaluation.
| Clinical Presentation of Congenital Cataracts |
|---|
| Leukocoria |
| Opacity in red reflex |
| Nystagmus |
| Strabismus |
| Photophobia/glare |
| Known systemic disorder associated with cataracts |
| Decreased visual interest |
| Developmental delay |
Examination
Work-up of pediatric cataracts includes a thorough review of the maternal history, including illness during pregnancy, drug use (therapeutic or illicit), and birth history. Historically, congenital rubella accounted for up to 20% of all congenital lens opacities, but this has been significantly reduced through immunization programs. Other infections reportedly associated with congenital cataract include toxoplasmosis, herpes, measles, mumps, and vaccinia. Exposure to radiation during pregnancy and maternal use of corticosteroids and sulfa drugs may result in lens opacities. A history of low birth weight or maternal malnutrition during pregnancy is reportedly associated with congenital cataracts.
Systemic Disorders
There are many systemic syndromes, both metabolic and/or genetic, whose features include lens disorders. All children with unknown genetic syndromes and syndromes with ocular involvement should have eye examinations as soon as possible. Often, the presence and specific type of opacity can lead to a systemic diagnosis. Although a comprehensive discussion of each of these syndromes is not appropriate here, a comprehensive list is provided (Table 20-1). The medical evaluation of children with cataracts can be quite extensive and costly, but associated abnormalities usually allow the pediatrician and geneticist to direct the work-up appropriately. The one disorder that must not be overlooked is galactokinase deficiency, which may cause a cataract in otherwise healthy children. Unlike galactosemia, in which the enzyme galactose-1-phosphate uridyl transferase is absent, resulting in numerous systemic findings, the absence of galactokinase may result in cataract only, and dietary intervention may reverse or halt disease progression.
Genetics
A family history of cataract may be elicited during the medical work-up. The various forms of inheritance, of which autosomal dominant is the most frequent, have been described elsewhere. Up to one third of congenital cataracts in healthy children are idiopathic, often representing new genetic mutations.1
Ophthalmic Examination
In infants and very young children it is not possible to measure formal visual acuity. However, findings such as searching nystagmus with bilateral cataracts or strabismus with cataract suggest extremely poor vision that requires rapid intervention.
| Evaluating Congenital Cataracts |
|---|
| Direct ophthalmoscopy or retinoscopy |
| Central opacity and/or surrounding distortion greater than 3 mm is significant |
| Slit lamp exam when possible |
| Rule out associated abnormalities of cornea, iris, or pupil |
| Hand held slit lamp or EUA |
| Rule out glaucoma (congenital rubella and Lowe’s syndrome) |
| Fundus exam or B scan |
In very young patients, multiple techniques are useful for evaluating the lens. The two basic techniques involve either direct slit lamp style viewing, or assessment of the lens opacity with respect to the red reflex. A portable slit lamp can be very helpful in evaluating the size, density, and location within the lens (anterior, posterior, central, etc.) of the opacity. The use of retinoscopy in a dilated eye allows the opacity to be visualized against the red reflex (back illuminated) and is extremely useful (Figs. 20-1 and 20-2). If the opacity is central, greater than 3 mm, and/or impeding retinoscopy or funduscopy, it is usually visually significant. A comparisonof bilateral lens opacities may be important to plan for timing and necessity of surgery on one or both eyes. If an adequate examination cannot be performed in the office, an examination under anesthesia is usually performed, with surgery immediately following the exam if appropriate. An attempt should be made to identify any associated ocular abnormalities either preoperatively or at the time of surgery because they may affect the prognosis and management. This includes strabismus, corneal size, corneal opacities, iris structure, glaucoma, microphthalmos, persistent hyperplastic primary vitreous, and retinal abnormalities. Particular attention should be directed to the lens in terms of size, shape, and position.
| Syndrome | Systemic Manifestations |
|---|---|
| Cataracts Associated with Skeletal Disease | |
| Albright’s hereditary | Short stature, subcutaneous calcification, osteodystrophy brachydactyly |
| Chondrodysplasia punctata | |
