1. What is Aniridia?
Simply put, aniridia is a genetic condition where there is little or no iris. In addition to the lack of iris, individuals with aniridia generally have other malformations of the eye that affect their vision.
2. Are people with aniridia blind?
No. Their vision may vary from 20/40 to 20/400. People with aniridia may be “legally blind” which is defined as vision that is not correctable to better than 20/200. However, this is quite different from total blindness. With 20/200 vision, one can still see colors, lights and the outline of large objects. In general, people with aniridia lack ‘detail’ vision and have better vision at close range.
3. What can someone with aniridia see?
It is difficult to say. Because the range of vision is different for each individual with aniridia, there is not one good description to explain what someone with aniridia can see. All people with aniridia will have challenges with seeing detail, due to the underdeveloped retina(foveal hypoplasia). Most pediatric ophthalmologists will tell parents of a child with aniridia “we will have to wait until he/she can tell us what he/she can see.” This can be very scary and frustrating. The sight of a child with aniridia can develop and get better over time.
4. Will their vision get worse over time?
It can. The non-degenerative parts of this condition are the lack of iris (it will never grow) and the foveal hypoplasia (the underdeveloped retina). These conditions will not worsen with time (other than the “normal” changes that occur with age and are correctable with glasses). However, the impact of the secondary conditions such as glaucoma, corneal pannus and cataracts can worsen one’s sight.
5. What causes the irregular eye movements?
This is a condition called nystagmus. The involuntary eye movements may be from side-to-side, up and down or rotary. Nystagmus is present to varying degrees in people with aniridia and typically declines with age. It tends to increase when the person is upset, excited or tired.
6. Does nystagmus affect vision?
Although people with nystagmus are not aware that their eyes are moving, it does make it more difficult for them to focus clearly on details. In fact, they often will find a “null point” which is the point where their nystagmus is the least apparent (see below).
7. What is the “null point”?
People with aniridia have a poorly developed fovea. In normal-sighted people, the fovea is in the center of the macula and an image will land there when the person is looking straight ahead. Their fovea is where they focus for their best detail vision – such as seeing a freckle on a person’s face. Because a person with aniridia has an underdeveloped fovea, they must find their best area of focus which may be anywhere on their retina. Typically, they will move their head to the position necessary to focus on this spot, consequently slowing their nystagmus and allowing for their best vision. This is their null point.
8. Is any of this correctable?
With the technology that is currently available, there are many treatment options for the secondary eye complications. First, there are instruments to measure eye pressure to keep glaucoma under control. If glaucoma is diagnosed, there are eye drops and/or surgeries to correct it. Also, there are surgical remedies for the corneal pannus such as stem cell transplants. Additionally, there are iris implants available to help decrease the amount of light that flows into the eye. However, this is not yet FDA approved. Please refer to the Aniridia’s Impact on Vision section to learn more about secondary conditions and current treatments.
9. How does someone get aniridia?
In most cases, aniridia is a genetic condition caused by an anomaly in the 11p13 section of the PAX6 gene; however other genes have been identified in relation to aniridia. The genetic problem can be sporadic (happens for the first time within either the egg, sperm, or shortly after conception) or familial (passed on from one parent). Unlike most genetic conditions, this is autosomal dominant, meaning it takes only one mutated gene to cause this condition. Aniridia is not contagious. There is a fifty percent chance of an aniridic passing it on to one’s offspring.
10. How can two people without aniridia produce a child with aniridia?
Both parents of a child with aniridia can be “normal,” having NO genetic mutation or deletion of the PAX 6 (or other indicated aniridia) gene. If these two people have a child with aniridia, the aniridia is called “sporadic,” The child obtained this genetic mutation or deletion from a spontaneous change in the egg, sperm, or soon following conception. The cause for this genetic mutation is not known. If these two parents should have another child, the chance of aniridia occurring in the next pregnancy is the same chance as any one else in the general population – very slim.
11. If an individual with aniridia has a child, what are the chances the newborn child will have aniridia?
Unlike most genetic conditions, aniridia is dominant. It only takes one parent to have the mutation or deletion to pass on this condition. Therefore, the chance of a man or woman with aniridia having a child with aniridia is fifty (50) percent. When someone with aniridia has a child with aniridia, the condition is called “familial” aniridia, because it was passed on by the parent with aniridia. With new technology, there is the possibility of identifying the mutation or deletion in the aniridia gene and using egg or sperm sorting to try to stop the aniridia from being passed on. This technology is very new and not much is known about its success rate.
12. How is aniridia diagnosed?
Aniridia can be diagnosed by an experienced ophthalmologist with a simple eye exam. In addition, there are genetic tests available as well. For more information on genetic testing, contact a qualified genetic counselor. Genetic counselors are generally affiliated with universities and/or children’s hospitals.
13. What is foveal hypoplasia?
The fovea is the part of the retina, in the center of the macula where one would normally focus for the sharpest most detailed vision. In people with aniridia, this area is poorly formed or, in some cases, not present. This is known as foveal hypoplasia.
14. Is aniridia associated with mental retardation?
In most cases, aniridia is caused by a mutation in the PAX6 gene and is not associated with mental retardation. However, there is a small chance in sporadic (non-inherited) aniridia that it is caused by a missing, or deleted PAX6 gene, rather than a mutation. In these cases, deletion of other genes in the same area results in WAGR syndrome (WAGR is an acronym for Wilms tumor, Aniridia, Genitourinary abnormalities, and mental Retardation). Although mental retardation is common in individuals with WAGR syndrome, neither mental retardation nor any of the other conditions is always present. For this reason, genetic testing is recommended for all infants born with sporadic aniridia. For more information on WAGR syndrome: http://www.wagr.org/
15. Should an individual with aniridia have ultrasounds to test for Wilm’s tumors?
Most pediatricians recommend that children with aniridia with a deleted PAX 6 be tested for Wilm’s tumors every 3 months, as the possibility is high if there is a deletion. There is debate as to whether children with only a mutated PAX 6 gene undergo ultrasounds. Many pediatricians believe this non-invasive ultrasound is a safeguard for catching tumors early. Early detection is KEY in fighting these cancerous tumors. Therefore, the consensus is “it can’t hurt” to get the ultrasounds. As to how often, the safest procedure is to have the ultrasound every 3 months until the child is eight years of age when the probability of the Wilm’s tumors decreases significantly. At that time, the monitoring is decreased to every 6 months or even annually. There has been a case of Wilm’s tumors being detected in a 24-year-old individual with aniridia, so the annual monitoring is a good idea.
16. Do people with aniridia have to go to special schools?
No. Most children with aniridia function well in a mainstream classroom, with proper accommodations.
17. Are there special services for children with aniridia?
Yes. It’s important for you to contact your county or state social service office to enroll your child in ‘Early Intervention Services’. Each state has different agencies dedicated to ensuring all children needing early services receive them. Even if you feel your child is developmentally on track, it’s important to be in contact with your local Early Intervention Services. The Center for Parent Information and Resources compiles information by state. Your pediatrician may be able to help connect you to the local agency, too, so don’t hesitate to ask about it.
18. Can people with aniridia read books?
Yes! Although Braille is typically not necessary for people with aniridia, a few may learn to use it in order to give their eyes a rest. Depending on the degree of visual impairment, other accommodations may be necessary. These include large print books, a CCTV, magnifiers, and high contrast materials. e-Readers (like the Kindle and iPad) have made a significant impact on the ability to read any book because one simply has to adjust the font size to accommodate.
19. Do people with aniridia spend a lot of time going to doctors?
Yes! It is very important for aniridia patients to closely monitor each eye and to see the correct specialist for each problem (glaucoma ophthalmologists, cornea ophthalmologists, pediatric ophthalmologists, etc).
20. How does the sun affect the eyes of people with aniridia?
Most people with aniridia are sensitive to light. Imagine a normally-sighted person with their eyes dilated at an eye doctor appointment. This is how the eye of someone with aniridia is at all times. Therefore, it is very important for them to wear sunglasses: a) for comfort and b) to protect the retina. One of the purposes of the iris is to protect the retina from too much sun. The retina can be damaged from too much sun exposure when an individual with aniridia does not wear sunglasses.
21. Can people with aniridia go outside?
Absolutely. With proper sunglasses, they can go anywhere, including the beach!
22. Are there other medical problems associated with aniridia?
Yes. Recent research indicates that other medical problems may be associated with aniridia (all types). These include: glucose intolerance, (thought to be a precursor to diabetes in some individuals) central auditory processing disorder (difficulty with discriminating and interpreting sounds) decreased or absent sense of smell, and subtle abnormalities in the structure of the brain, such as decreased size or absence of the anterior commissure and/or the pineal gland. When aniridia occurs as part of WAGR syndrome, there may be medical problems in addition to those listed above. More information on these can be found here: http://www.wagr.org/.
23. Can people with aniridia drive a car?
Sometimes. The requirements vary by country and by state. They may be required to wear a bioptic device to drive. For details, please see http://www.biopticdriving.org/
24. My child was just diagnosed with aniridia, what should I do?
Refer to the Newly Diagnosed – Aniridia section for more information.
25. What can I do to help my child ‘make the most’ of their functional vision?
Because your child’s functional vision is dependent on many factors, it is important to get in touch with a qualified low-vision specialist to assess tools that may help your child. To find a low-vision specialist in your area, google ‘low-vision specialist’ + <your city>.
26. How can I find a qualified doctor in my area?
Aniridia is a rare condition. It is important that you find a doctor that has a base of patients with aniridia because some treatments that are common for some secondary conditions are contraindicated for individuals with aniridia. Ask your doctor how many patients he or she has with aniridia. If you are not comfortable or would like a second opinion, post a comment on the ‘United Families of Aniridia’ Facebook page asking for the type of specialist (e.g. pediatric ophthalmologist, glaucoma specialist, cataract specialist, etc.) needed and in which area of the country you live. Many people with aniridia choose to travel far distances to receive the correct medical attention.
27. Sunglasses and hats are recommended throughout this website, can you recommend brands?
We find many families like the Julbo-brand sunglasses in the ‘Looping’ style for babies because they are comfortable, the lenses are dark, and they are form-fitting which does not allow light to come in from the sides or above. Baby hats can be found in many retail establishments. We like Sunday Afternoons because they are lightweight, high-quality, and portable.
28. How can I meet others with aniridia?
You can start by contacting email@example.com. Debby has been our Family Support Liaison for several years. Her son has anidiria and she can share her experience as well as offer suggestions for connecting with other families.