Q: What is aniridia?
A: A congenital disorder which causes low vision and/ or blindness, characterized by a lack of iris in the eyes, in addition to the possibilities of other medical issues such as diabetes, glaucoma, and kidney problems.
Q: Is there a cure for aniridia?
A: No, currently there is not, however a variety of treatments are being tested in hopes of finding a cure in the near future.
Q: Is aniridia inherited?
A: It can be. In parents who have aniridia, there is a 50% chance of passing it onto their offspring, which accounts for ⅔ of the reported aniridia cases. It is an autosomal dominant trait, known to be found in the recessive hereditary pattern, which means one copy of the altered gene per cell is enough to cause the disorder.
Q: What is Sporadic Aniridia?
A: Sporadic Aniridia is found in children in which neither of their parents has aniridia. This type of aniridia predisposes those who have it to a greater risk of Wilms’ tumor, and regular ultrasounds until age 8, are required to screen for it.
Q: What is WAGR syndrome?
A: WAGR is an acronym comprised of the different conditions that often occur together in those with aniridia. 30% of sporadic aniridia cases have the potential to include WAGR syndrome. It is comprised of:
W: Wilms’ Tumor, a rare variation of kidney cancer known to affect children primarily.
G: Genitourinary (reproductive/ urinary) abnormalities.
R: (mental) Retardation
Q: Is it possible for mental retardation to be caused by aniridia?
A: In cases of sporadic aniridia, there is a small chance of mental retardation due to the possibility of a missing or deleted PAX6 gene, which is different than when the disorder is caused by gene mutation. In these circumstances of gene deletion, when other genes located in the same area are also deleted, the result is WAGR syndrome. However, retardation is not guaranteed to be present in all individuals with WAGR.
Q: What are the most common effects of aniridia?
A: Commonly, those with aniridia experience extreme light sensitivity, also known as being photophobic. The function of the iris blocks and absorbs some of the light which enters the eye, and not having iris can create excessive glare upon the eyes.
Q: Are people with aniridia legally blind?
A: Oftentimes, yes, however the effects of the disorder can vary greatly between individuals, ranging from mild to extreme ocular abnormalities. Most children born with aniridia have vision around 20/200, which classifies as legally blind. Additionally, eyesight is expected to get progressively worse for children born with this disorder as they age, because the associated conditions of Aniridia Fibrosis syndrome (AFS), glaucoma, corneal scarring, cataracts, and retinal detachments are known to cause further vision loss.
Q: Are babies born with aniridia able to see?
A: The levels to which babies born with aniridia syndrome can see vary, however considering that the disorder is marked by underdeveloped eye structures, it is estimated that vision for those with aniridia is 20/80 to 20/400. The lack of an iris alone will not cause blindness, though the other associated conditions, such as cataracts, glaucoma, and corneal scarring, that can come as side effects of aniridia can majorly impact the ability to see.
Q: Can aniridia occur in one eye, or does it occur in both simultaneously?
A: Generally, symptoms are found in both eyes.
Q: What is nystagmus?
A: It is a condition commonly associated with aniridia, and it is marked by involuntary irregular eye movements, in which the eye moves up and down, side-to-side, or rotary. It is present in people with aniridia in varying degrees, and it is known to decline with age. It is also known to increase with excitement, strong emotion, or when tired. The person experiencing nystagmus will not be aware that their eyes are moving, however they will find it difficult to focus clearly, or see details.
Q: When does glaucoma usually set in for aniridia patients?
A: Most commonly, glaucoma appears in early adulthood/ adolescence.
Q: What is the frequency of aniridia occurrence?
A: Throughout the world, aniridia occurs somewhere in the range of 1 in 50,000 to 1 in 100,000 babies born. Source: https://ghr.nlm.nih.gov/condition/aniridia#statistics
Q: How is Aniridia Diagnosed?
A: Aniridia is most often diagnosed by clinical examination by an experienced opthamologist, as well as via genetic testing using sequence analysis of the PAX6 coding region, as well as deletion / duplication analysis to uncover the PAX6 exon or the whole-gene deletion. This procedure identifies the pathogenic variant in cases of isolated aniridia. In those with WAGR syndrome, using high-resolution cytogenetic testing to examine the disease-causing mechanism, deletions of PAX6 and WT1 can be identified to get a correct diagnosis.
Q: How can aniridia be managed, since there isn’t a cure?
A: There are a variety of treatments, and the course of which depends on the patient being treated, as well as the severity of their symptoms. It is to be expected that those with aniridia will undergo continuous monitoring of their condition throughout life. Tinted or specialized photochromic lenses that reduce light sensitivity, specialized polarized sunglasses, occlusion therapy, corrective spectacles for refractive errors, and closed-circuit television used as a low-vision aid are often employed as methods for management. Opaque contact lenses are sometimes used to help minimize glare and photophobia, as well as for cosmetic purposes.
Some aniridic individuals may have the option of having a surgically-placed artificial iris implant, however this method has the potential for complications, and it has not yet been FDA approved.
For those with aniridia and dense cataracts, cataract extraction can often prove helpful in improving visual acuity. In cases of glaucoma, topical treatments of anti-glaucoma medication are generally the first course of action. A range of other methods are used, depending on the circumstances and the symptoms the patient is experiencing, in an effort to manage the disorder. It is recommended that children under the age of 8 who have aniridia, be monitored continuously every 4-6 months to check the status of their refractive errors and amblyopia. Yearly glaucoma screening is recommended, as well as for aniridic fibrosis syndrome. (Source: http://www.aapos.org/terms/conditions/26)