WHAT IS ANIRIDIA?/DIAGNOSIS

1. What is the genetic origin of this illness?

Aniridia is produced by a failure in the development of the ocular globe during pregnancy, due to a genetic mutation, a deletion in the short arm of pair 13 of the 11th chromosome, a scarcity of proteins in the DNA in the Pax 6 gene, responsible for the formation of the eye. This is why in the majority of the cases other parts of the eye are also affected, and even other organs of the body in the more exceptional cases.

2. How is it detected?

A newborn child with aniridia closes its eyes when facing a light source and feels more comfortable in semidarkness. Photophobia is the principal symptom of an eye without an iris.

3. What should parents do in this situation?

When parents are alerted to this reaction, they should take the child to an ophthalmologist to determine the degree of the disease and to be informed about other associated disorders and the examinations the child should undergo.

During the first years of life, the child should be examined to discard the possibility of lesions in the kidney and in other parts of the body. Regarding his sight, the child should see the ophthalmologist at least once a year, and during his first few years, every three to six months, to detect high ocular pressure.

They can also contact the Spanish Association of Aniridia, where they will be informed of all they need and where they can interchange experiences with people who have more or less the same problems or who have gone through the same situation.

4. What visual acuity do they have?

This depends on the associated disorders, but in principle, the failure in retinal and optic nerve development causes low visual acuity, from 20% to 10%, and even lower if the aniridia is accompanied by serious ocular disorders, such as glaucoma or congenital cataracts.

They have difficulty in distinguishing distant objects with clarity, precision and relief, therefore the affected person will get very close to the objects.

They will suffer from the glare of an intense light or from abrupt changes in light, and have difficulty distinguishing the details of an object or a person against the light. They are more comfortable sitting with their back to a window, but when reading, they should have sufficient light and it should focus directly on the paper, without shadows or reflections on glass or mirrors.

5. How can I explain his problem to my child?

Since aniridia is a problem that the child has since birth, he will progressively become aware of his problem. The child will realize his greater difficult in reading, in distinguishing certain objects or in carrying out certain activities in comparison with other children. Therefore, (1) it should be explained to the child that he has a very large pupil, and for this reason the light hurts him, and therefore, he should use sunglasses and other visual aids necessary to carry out certain activities. (2) He should be told the truth naturally, never dramatizing the problem, so that he grows up without complexes, and be encouraged to live life as much as possible as other children of his age, always assuring him that he can count on our support and help. (3) Whenever possible and his vision permitting, the child should attend any school where, with visual aids and the cooperation of his teacher, who should be informed about the problem, the child can carry out the same activities as his classmates and feel integrated.

If necessary, the ONCE (National Organization for the Blind of Spain) has centers where affiliates (blind and visually impaired) of this organization can study.

6. Can their vision be improved?

It depends on their visual acuity and the disorders they may have, but in infancy they can be stimulated to develop their vision and psychomotricity; and in difficult cases, the help of a psychologist should be beneficial in the development of their personality.

They should wear sunglasses to protect the eye from an excess of light and avoid further visual damage. Cosmetic lens with artificial pigmented irises improve photophobia and diminish nystagmus, although in some cases, vision is not improved. They are not recommended for people with corneal disorders.

Generally, conventional lens do not improve visual acuity in these patients, for which reason they must use low-vision aids.

7. What are the low-vision aids?

Visual aids vary from glasses with magnifying lens to a mini-telescope, lectern, notebook pages with large squares, books with large letters, tele-magnifier, lamp with magnifying glass and light incorporated, computer programs, etc., depending on each particular case. These visual aids can be found in the ONCE and in optical departments specialized in low vision.

8. Is aniridia hereditary?

There are two types of aniridia: hereditary and sporadic.

In sporadic aniridia, there is no family history of this disease. From this moment it becomes hereditary. According to the data this Association has available, more than half of the people affected by aniridia have no antecedents. This group has a higher risk of suffering Wilms tumor and other problems.

Aniridia’s heredity is autosomally dominant; that is, the carrier of the illness transmits it to approximately 50 percent of his direct descendants.
Five percent of aniridics have Wilms tumor or WAGR Syndrome.

Two percent suffer from cerebellar ataxia, which is the autosomally recessive form.

We hope that in the future the transmission of aniridia can be interrupted through amniocentesis or artificial insemination.

Families affected by aniridia are advised to undergo a genetic study.

9. Frequency or incidence in the population

In Spain, no studies are available, but it is estimated that one in every 80,000 or 100,000 persons have aniridia. As it is a low-incidence disease, most professionals do not have the opportunity to treat sufficient cases and accumulate experience on diagnosis, prognosis and surgical results that help to advance the study of this disease.

10. Social and labor integration:

Society’s knowledge of the illness is very important because of the social rejection that persons with aniridia suffer in many cases:

In school: from schoolmates because they wear sunglasses or use visual aids, get close to the paper, or because they look different, or because they play poorly at certain sports in which precision is necessary or where good distance eyesight is required such as, for example, soccer or tennis. They have to suffer their schoolmates’ making fun of them, which is why parents should be very understanding with them at home and give them plenty of support.

In the workplace: Similar situations can occur in the workplace, worsened perhaps by competition for a position.

In case of an accident, besides other constants, the eye is observed to see if the pupil is dilated, a symptom of death, and for this reason it is very important that people know about aniridia to avoid errors like these, since the dilated pupil can also be considered a symptom of other illnesses that aniridics probably do not have.

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