Eye Matters
September 16, 2005

Congenital Cataract – Preventable blindness

In one of our previous encounters we talked about the different types of cataract that exist: senile seen from ages 60-65 years (the most frequent of all), metabolic seen in diabetic patients, secondary cataract ( trauma, ocular inflammation, surgical interventions for glaucoma, retina etc), immunological and congenital. We will dedicate our talk today to this last one as it occupies the number one spot in producing preventable blindness in infants.{{more}}

We will remind ourselves that the main function of the lens (crystalline) is to allow images to be focused sharply on the human retina ( thin membrane found at the back of the eye vital for our vision). When the lens is opaque our vision is severely affected. A congenital cataract involves clouding of the lens of the eye that is present at birth.

Congenital cataract can be unilateral (in one eye) or bilateral (in both eyes), the latter being the more common and at the same time with better evolution once treated properly. Its incidence is 1-3 in every 10 000 children, this number being somewhat greater in under developed countries.

This type of cataract is always a challenge for the ophthalmologist because the eye’s anatomy first has to be restored and other secondary afflictions treated for example amblyopia (lazy eye or underdevelopment of the visual system), strabismus and nystagmus.

Luckily the number of people born with cataract is low, with the possible causes including congenital infections (toxoplasmosis, syphilis, rubella, cytomegalovirus, Herpes simple virus), metabolic (galactokinase deficiency), Down’s syndrome, Turner’s syndrome, Wilson’s disease etc.

Why is the child brought to the ophthalmologist clinic? In occasion a white spot is noted in the pupils or the child is simply referred to us by a General practitioner or Pediatrician.

A correct evaluation requires a thorough history taking including the pregnancy and delivery and the family history. Interconsultation with the pediatrician is very important as well as an exhaustive eye examination accompanied by blood tests, urine analysis etc.

How are these patients treated? If the cataract is unilateral only with partial or total cloudiness of the lens, surgery must be done within four weeks after birth so that ocular rehabilitation can be started and the patient can develop a useful vision. In patients where it is bilateral and the cloudiness of the lens is less than three millimeters, the surgery can be prolonged with the patient kept under strict surveillance by their ophthalmologist and the surgery is almost always done before their second birthday. The operation is done under general anesthesia and antibiotics and anti-inflammatory medications are prescribed in the post operative period. The child might also be required to wear glasses or contact lens in this period as well if an intra-ocular lens was not placed in the eye during the surgery.

We should always bear in mind that the development of our vision starts at birth and continues until around seven years of age so that what our brain has not learnt to recognize in this period would be lost for life, therefore it is very important to take your child to the ophthalmologist if he/she has been diagnosed with congenital cataract or you suspect that they might have the same.

Do not forget my fellow reader that our children are the hope of tomorrow’s world.