Congenital Cataracts
Introduction
Congenital cataracts are opacifications of the lens present at birth or developing shortly thereafter. They are a leading cause of preventable childhood blindness worldwide.
Key Points:
- Prevalence: 1-6 per 10,000 live births
- Accounts for 10% of childhood visual impairment globally
- Critical period for intervention: first 6-8 weeks of life
- May be isolated or part of systemic disease
- Bilateral in 50% of cases
Classification
1. Morphological Classification:
- Total Cataract
- Complete lens opacity
- Worst prognosis if untreated
- Nuclear Cataract
- Central opacity
- Most common type
- Often hereditary
- Lamellar Cataract
- Shell-like opacity
- May be progressive
- Polar Cataract
- Anterior or posterior
- May be associated with persistent fetal vasculature
- Sutural Cataract
- Y-shaped opacity
- Often minimal visual impact
2. Based on Laterality:
- Unilateral - Often sporadic
- Bilateral - More likely hereditary or systemic
Etiology
1. Genetic Causes (25-50%):
- Isolated Inheritance
- Autosomal dominant (most common)
- Autosomal recessive
- X-linked
- Genetic Syndromes
- Down syndrome
- Lowe syndrome
- Nance-Horan syndrome
- Alport syndrome
- Wilson disease
2. Intrauterine Infections (TORCH):
- Toxoplasmosis
- Rubella (most common)
- Cytomegalovirus
- Herpes simplex
3. Metabolic Disorders:
- Galactosemia
- Hypocalcemia
- Diabetes mellitus (maternal)
- Fabry disease
Clinical Features
Common Presentations:
- Leukocoria (white pupillary reflex)
- Strabismus
- Nystagmus
- Poor visual behavior
- Failed red reflex testing
Associated Features:
- Microphthalmos
- Persistent fetal vasculature
- Anterior segment dysgenesis
- Posterior segment abnormalities
Systemic Associations:
- Developmental delay
- Cardiac defects
- Skeletal abnormalities
- Hearing impairment
Diagnosis
Ophthalmic Evaluation:
- Red Reflex Testing
- Essential newborn screening
- Performed at birth and 6-8 weeks
- Detailed Examination
- Slit lamp examination
- Dilated fundus examination
- Ultrasound if needed
- Keratometry and axial length measurement
Systemic Workup:
- Laboratory Tests
- TORCH titers
- Blood glucose
- Calcium profile
- Galactosemia screening
- Urine analysis
- Genetic Evaluation
- Family history
- Genetic testing
- Chromosomal analysis
Management
Principles of Management:
- Early detection critical
- Timing of surgery crucial
- Long-term visual rehabilitation essential
Surgical Management:
- Timing
- Bilateral: 6-8 weeks of age
- Unilateral: 4-6 weeks of age
- Surgical Options
- Lensectomy
- Posterior capsulotomy
- Anterior vitrectomy
- IOL implantation (age-dependent)
Post-operative Care:
- Visual Rehabilitation
- Contact lenses/Spectacles
- Aggressive amblyopia therapy
- Regular monitoring
- Complications Management
- Glaucoma monitoring
- PCO management
- Inflammation control
Long-term Follow-up:
- Regular refraction
- Amblyopia monitoring
- IOP monitoring
- Visual development assessment
