A: All children should have their eyes checked, usually by a paediatrician or senior nurse, to make sure that they have a normal red reflex in each eye. This means that the media of the eye (the cornea-window of the eye; and lens, are clear). In aniridic children it often appears as though they have 'big' pupils which can be misleading. Nystagmus ('wobbly eyes') which can be present in eyes with Aniridia is not usually present at birth.
Q: If you are not sure about your child opening their eyes or closing them in bright light obviously, what should you do?
A: Seek an opinion from a paediatric ophthalmologist. This is best done by going to your GP and expressing your concerns.
Q: If Aniridia is diagnosed, how would you advise the new parent?
A: It is important to make sure that there is no family history. It is also important that both parents are examined. This is because Aniridia can exist with the iris still being present...the iris (coloured part of the eye) is just thinner but not absent. So both parents should be examined.
When diagnosis is made...don't panic. Ask the Doctor whether there are any cataracts and what the fovea looks like (central 'seeing part' of the retina - the film at the back of the eye). In Aniridia this can be under developed and can cause reduced vision and nystagmus. Not all children with Aniridia develop nystagmus. Also ask the Doctor if your child has Glaucoma. This can develop in up to 50% of cases. Sometimes however it is present from or soon after birth.
Q: What genetic testing should be carried out as routine alongside this diagnosis?
A: Sporadic Aniridia (no family history) can be associated with a tumour of the kidney called Wilms Tumour. To ensure that this is not the case, the child should have a special chromosome test to see if there is a deletion on the short arm of chromosome 11. This is called 11p...the specific region on this short arm is '13' so we call it 11p13.
The child should also have an analysis of the gene, mutations of which can cause Aniridia. This is called PAX6. Until these genetic tests are back, the child should have 3 monthly renal ultrasound scans to make sure there is no renal tumour.
If there is a deletion which involves the gene that causes Wilms Tumour, then the child will need review by a renal (kidney) Doctor. If there is no deletion and there is only a mutation within the PAX6 gene then the child is no longer at risk of developing Wilms Tumour.
Q: If surgery is suggested (if cataracts are present) is it advisable to seek a second opinion?
A: It depends why the surgery is being offered. If the child has bad glaucoma (pressure in the eye is raised) then there may not be time for second opinions. If there is a dense cataract then it is best to get surgery done before 6 weeks of age (if it affects only one eye) and before 8 weeks of age if it affects both eyes.
Q: What advice would you give to parents about protecting their child's eyes?
A: Children with Aniridia can dislike light due to the lack of iris to reduce light entry into the eye. Sun hats when young and sunglasses when older are a good idea. Polychromatic lenses (ones which react to light) can be a good choice for older children.
Q: What is the average sight like for an aniridic?
A: This depends on whether the fovea (see above) is under developed (hypoplastic) or not. If it is, vision can be poor (6/36-6/60) and there is associated nystagmus. If it is not under developed, then vision can be good (6/12-6/18) with no nystagmus.
Q: Can you advise of anything else important in the early stages?
A: Keep your spirits up. Remember you have a beautiful child.
Q: People ask a lot about 'fake irises' and stem cell transplants - would you say that the science is there yet with using either of these in children?
A: Nowhere near clinical trials yet for stem cells in children. Artificial irises in infants are not a good idea. Too much danger of inflammation and haemorrhage.
Mr Nischal is Head of the Clinical and Academic Dept. of Ophthalmology at GOSH.
We would like to thank him very much for his time and support to answer our questions, if you have any you would like answering, please contact us and we will endeavour to have your questions replied to.