KEY POINTS
- 1.
Cataracts are inherited or sporadic; congenital or acquired; isolated or in a syndrome.
- 2.
Size, density, and location of lens opacity influence its visual significance.
- 3.
Timing of cataract surgery is important; earlier detection and surgery have better outcomes.
- 4.
Primary congenital glaucoma is the most common form of glaucoma in infants. It usually requires surgical treatment.
- 5.
Some forms of infantile glaucoma may be managed with topical antihypertensives but may also require surgery.
Congenital Cataract
Cataracts develop due to disturbances in the normal highly ordered cellular arrangement of the crystalline lens. Pediatric cataracts remain a significant cause of preventable blindness. However, the related vision loss can be greatly mitigated with prompt identification and treatment of significant lens opacities. In the United States, prevalence is estimated at 13.6 per 10,000 infants, with 3.0 to 4.5 per 10,000 being visually significant. The role of the neonatologist and pediatrician in early detection and prompt treatment cannot be overstated.
Presentation
History
Because congenital cataracts are often associated with genetic diseases or syndromes, a comprehensive history assists in diagnosis and management. Concerns about a white spot in the pupil, nystagmus, strabismus, asymmetric size of one eye relative to the other, photophobia, or visual inattentiveness should prompt referral. A detailed medical history includes documenting the onset of symptoms, such as whether prior exams documented a normal red reflex, birth weight, prematurity, evidence of maternal infection (especially TORCH infections [toxoplasmosis, other agents, rubella, cytomegalovirus, or herpes simplex], rash, or febrile illness during pregnancy), pertinent prenatal and perinatal history (i.e., radiation, alcohol, or drug exposure), maternal travel, history of ocular trauma, and corticosteroid therapy.
Family history is important. A complete ocular examination is needed within the first few weeks after birth in infants with a family history of childhood cataract, particularly if it is bilateral. Hereditary bilateral cataracts are often inherited in an autosomal dominant (AD) pattern with a high degree of penetrance. A history of consanguinity can help in identifying the risk of genetic disorders associated with congenital cataracts.
Examination
For infants with bilateral cataracts, parents and caregivers can provide information on visual interest. In neonates, the significance of a cataract is determined primarily by examination. Later, visual fixation, following faces, and reaching for objects are important milestones. For monocular cataracts, squinting, crossing, or wandering of an eye, a face turn, or opposition to blocking vision in one eye can allude to poor vision in the setting of lens opacity.
The Bruckner Red Reflex Test can be used to detect and determine the density of a lens opacity. Both eyes are viewed using a direct ophthalmoscope at a distance of approximately 3 feet to compare the red reflexes. The light reflex is normally symmetric in both eyes.
Infants with uni- or bilateral cataracts can develop nystagmus due to poor vision. Those with bilateral, dense cataracts often develop nystagmus by 3 months of age, which is when the fixation reflex normally develops.
Congenital cataracts can be classified based on morphology, location, laterality, and/or etiology ( Fig. 65.1 ). Although a detailed description of each type of cataract is beyond the scope of this text, the neonatologist must remember several characteristics that make cataracts more visually significant and thus amblyogenic: large and dense opacities, central and posterior location, unilaterality, or association with a persistent fetal vasculature (PFV). Cataract type is a critical determinate of outcome and can assist in narrowing a genetic diagnosis.
AD-inherited bilateral nuclear cataracts are usually an isolated finding (see Fig. 65.1 ); these can be variable in density and visual significance and are often visible with a simple bedside penlight exam as a centrally located, white opacification obscuring the visual axis. In a recent large, US-based cataract registry, family history was present in 18% of 994 children.
In contrast, PFV cataracts are typically unilateral and the eye is often microphthalmic. A fibrovascular stalk may connect the posterior lens capsule to the optic nerve and can cause a tractional retinal detachment if it extends to the retina. Angle closure glaucoma may also occur if the retrolenticular membrane contracts. Aphakic glaucoma commonly occurs after removal of a PFV cataract. Visual outcomes are generally quite poor.
Many hereditary cataracts present at birth, although many worsen with age and may be detected only in later years. Cataracts may be the first, or a later, presenting sign of a systemic disorder. Lamellar or zonular cataracts are usually inherited in an AD fashion and are among the most common type of inherited childhood cataracts (see Fig. 65.1 ). Usually bilateral, the opacities are not visually significant unless they progress to involve the lens cortex or nucleus. Table 65.1 summarizes inherited cataracts related to systemic disorders. Physical examination can help tailor investigations to identify syndromic associations.
| Condition | Ocular Findings | |
|---|---|---|
| METABOLIC | ||
| Galactosemia | Cataracts (lamellar) | |
| Fabry disease | Cataracts (posterior subcapsular) | |
| Hyperglycemia | Cataracts | |
| Mannosidosis | Cataracts (posterior subcapsular) | |
| Refsum disease | Cataracts | |
| Wilson disease | Cataracts (sunflower) | |
| Multiple sulfatase deficiency | Cataracts | |
| RENAL | ||
| Lowe syndrome | Cataracts (multiple forms), glaucoma | |
| Alport syndrome | Cataracts (anterior lentiglobus) | |
| MUSCULOSKELETAL | ||
| Myotonic dystrophy | Cataracts (Christmas tree) | |
| Chondrodysplasia punctate | Cataracts | |
| Stickler syndrome | Cataracts, glaucoma | |
| Albright hereditary osteodystrophy | Cataracts | |
| Robert syndrome | Cataracts | |
| Majewski syndrome | Cataracts | |
| DERMATOLOGIC | ||
| Cockayne syndrome | Cataracts | |
| Rothmund-Thomson syndrome | Cataracts | |
| Sturge-Weber syndrome | Glaucoma | |
| Juvenile xanthogranuloma | Glaucoma | |
| Neurofibromatosis | Cataracts (PSC), glaucoma | |
| Oculodermal melanocytosis | Glaucoma | |
| OTHER | ||
| Rubinstein-Taybi syndrome | Cataracts, glaucoma | |
| Smith-Lemli-Opitz syndrome | Cataracts | |
| Cerebro-oculo-facial-skeletal syndrome | Cataracts | |
| Kabuki syndrome | Glaucoma | |
| CHROMOSOMAL ABNORMALITIES | ||
| Trisomy 13 | Cataracts, glaucoma | |
| Trisomy 18 | Cataracts | |
| Trisomy 21 | Cataracts | |
| Turner syndrome | Glaucoma | |
In-utero maternal infections, trauma, and exposure to therapeutic agents (i.e., corticosteroids or radiation) are noninherited causes of congenital cataracts. Lens opacities tend to develop later in neonates exposed to steroids or radiation. Traumatic injury to the lens has been reported to occur in infants treated for retinopathy of prematurity.
Workup and Management
Laboratory Investigations and Tests
Please see the online version for details. Most congenital cataracts are idiopathic, especially when unilateral. Up to 86% of unilateral and 68% of bilateral cataracts have no discernable cause. There may be associated eye anomalies in up to one-fourth of eyes with cataracts.
TORCH screening should be done in infants with maternal TORCH infections or if microcephaly, thrombocytopenia, and hepatomegaly are present. Bilateral cataracts, hypotonia, failure to thrive, and developmental delay may indicate a possibility of a metabolic disorder. Next-generation sequencing may be useful. A genetics consultation is important for these infants.
Examination Under Anesthesia
An exam under anesthesia (EUA) is recommended with preparation for possible cataract removal, with measurement of intraocular pressure, corneal diameter, a complete eye examination with refraction, and retinoscopy. Determination of corneal curvature and globe axial length helps in surgical planning, intraocular lens power calculation, and prognostication. If there is poor view to the posterior pole, B-scan ultrasonography is done to make sure that there is no associated retinal pathology or PFV prior to proceeding with surgery.
Preoperative Planning
Please see the online version for details. Lens opacities obscuring >3 mm of the red reflex are visually important. Cataract extraction earlier than 4 to 8 weeks may have more ocular complications, especially glaucoma. The surgeon can wait until 4 to 6 weeks in unilateral and up to 10 weeks in bilateral cases with less risk of amblyopia and glaucoma development. In infants with bilateral cataracts, the second eye surgery should be performed within 1 to 2 weeks.
Operative Approach and Issues
The objective of surgery is to clear the visual axis by removing the opacified lens. The details of the surgical procedures are outlined in the online version.
Postoperative Management
After surgery, an eye patch and/or shield is placed over the operated eye for 24 hours, and close monitoring is needed. The infant needs to wear corrective lenses and adhere to amblyopia therapy to lower the risk of later strabismus. , Please see the online version for details.
Complications and Long-Term Prognosis
Posterior capsular opacification, glaucoma, intraocular hemorrhage, inflammation, infectious endophthalmitis, and retinal detachment can occur after cataract surgery. Please see the online version for details. , , ,
Glaucoma
Infantile glaucoma includes a heterogeneous group of eye disorders characterized by optic neuropathy, increased intraocular eye pressure (IOP), vision/visual field loss, and anatomic changes related to this pathophysiology. Although rare in children without cataract, it can have irreversible vision-threatening consequences if not addressed promptly.
Glaucoma may occur in infants due to an abnormality in aqueous outflow, often with a genetic etiology. Secondary glaucoma results from an underlying ocular or systemic disease, trauma, or medication. Some glaucoma in childhood can have both primary and secondary origins, such as in Sturge-Weber syndrome or neurofibromatosis.
Primary congenital glaucoma (PCG) is a frequently seen cause of primary glaucoma in infants (1 in 10,000–20,000 live births; Fig. 65.2 ). Most cases (>75%) present with bilateral disease, although the severity may be asymmetric. About 15% of cases present with a classical triad of photophobia, epiphora (tearing), and blepharospasm (frequent blinking). More frequently, the condition is seen as a hazy or cloudy cornea and buphthalmos (see Fig. 65.2 ). “Buphthalmos,” or eye enlargement, is derived from the Greek word bous (ox or cow) due to the resemblance of eyes in infants with high IOP to large bovine eyes. CYP1B1 mutation in the GLC3A locus and LTBP2 mutation in the GLC3C locus have been linked to PCG.
