CONGENITAL / INFANTILE
The term cataract is used for any opacification of the crystalline lens, the natural lens of the eye. So, it is easy to understand the visual impairment that cataract can cause.
Cataract is an alteration typical of elderly persons, and its natural development is due to the cumulative effect of light. Nevertheless, it may appear at any age.
In children, it may exist at birth – congenital cataract, or it may develop during childhood – infantile or juvenile cataract. In these cases, it is usually associated with other diseases.
The way congenital or infantile cataract is evaluated and treated is completely different from adult cataract.
Congenital / infantile cataract is the most serious form, because of its potential to hinder the normal development of eyesight!
If a congenital cataract obstructs the visual axis, a prompt intervention is required, preferably between the 1st and the 2nd month of life. In this period of infancy the cerebral cortex develops all its functionality, and so, if during the first 3 or 4 months of life the image it receives is of bad quality, the cerebral sight will be severely and irreversibly impaired.
Is congenital cataract very frequent? Is it an important cause of blindness?
The incidence of congenital cataract ranges from 1.2 to 6 in 10,000. This type of cataract is responsible for 5 – 20% of the cases of blindness worldwide and for 10% of all the cases of infantile blindness.
In 64% of the cases, congenital cataract is present in both eyes.
In almost 2/3 of the cases (63%) of congenital / infantile cataract it is not possible to know the cause, even after a rigorous clinical investigation.
In 29% of the cases there is a genetic cause: cataract may be hereditary or it may be associated with syndromes and/or chromosomal defects. Intrauterine infections (rubella above all) can also be the cause of congenital cataract.
Furthermore, cataract may be associated with other ocular disorders such as aniridia, colobomas and foetal vascularization persistence.
Main causes of cataract in infancy:
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METABOLIC
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SYSTEMIC DISORDERS
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DYSMORPHIC SYNDROMES
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INTRAUTERINE INFECTIONS
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Galactosemia
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Trisomy-21
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Sindrome de Nance Horan
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Toxoplasmosis
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Galactokinase Deficiency
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Turner’s Syndrome
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Hallermann – Strieff’s Syndrome
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CMV
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Hypocalcaemia
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Trisomy-13
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Lowe’s Syndrome
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Herpes
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Hypoglycaemia
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Trisomy-18
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Conradi’s Syndrome (rhizomelic chondrodysplasia)
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Varicella
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Mannosidosis
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“Cri du chat” Syndrome
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Peroxisome diseases
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Syphilis
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Hyperferritinaemia
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Martsolf’s Syndrome
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Rubella
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COFS Syndrome
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Cataract can be detected by an alteration of the normal red reflection coming from the eye. If this reddish uniform reflection appears altered, the child should be urgently referred to an ophthalmologist.
The alteration of the red reflection depends on the MORPHOLOGY of the cataract, which presents a wide spectrum, going from a small opacity of the anterior capsule (small stain in the reflection) to total opacity (absence of reflection, or leucocoria if the opacity acquires a white aspect). The larger and/or more posterior the opacification of the crystalline lens is, the more serious the functional effect will be and more urgent the intervention of the ophthalmologist should be.
Treatment
It depends on the functional effect of cataract. If visual acuity is significantly reduced, because of an important obstruction of the visual axis, the treatment is surgical and should be performed at a very early stage, before the development of nystagmus and strabismus.