Aniridia, sporadic

A rare genetic disorder affecting the eyes

Aniridia
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Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Absence of the iris, vision problems
Complications	Glaucoma, cataracts, nystagmus, foveal hypoplasia
Onset	Congenital
Duration	Lifelong
Types	N/A
Causes	Genetic mutation (often sporadic)
Risks	N/A
Diagnosis	Clinical examination, genetic testing
Differential diagnosis	N/A
Prevention	N/A
Treatment	Symptomatic management, vision aids
Medication	N/A
Prognosis	N/A
Frequency	Rare
Deaths	N/A

Aniridia is a rare congenital condition characterized by the complete or partial absence of the iris of the eye. This condition can lead to a variety of vision problems and is often associated with other ocular and systemic abnormalities. Aniridia can occur as part of a syndrome or as an isolated condition. When it occurs without a family history or associated syndromes, it is referred to as sporadic aniridia.

Etiology

Sporadic aniridia is typically caused by a de novo mutation in the PAX6 gene, which plays a crucial role in eye development. The PAX6 gene is located on chromosome 11p13. In sporadic cases, the mutation arises spontaneously, meaning there is no prior family history of the condition.

Clinical Features

Individuals with aniridia may present with:

• Partial or complete absence of the iris: This is the hallmark feature of aniridia, leading to reduced visual acuity and increased sensitivity to light (photophobia).
• Vision problems: These can include nystagmus, strabismus, and reduced visual acuity.
• Associated ocular conditions: Patients may develop glaucoma, cataracts, and foveal hypoplasia.

Diagnosis

Diagnosis of aniridia is primarily clinical, based on the characteristic appearance of the eyes. Genetic testing can confirm mutations in the PAX6 gene. It is important to differentiate sporadic aniridia from syndromic forms, such as WAGR syndrome, which includes Wilms' tumor, aniridia, genitourinary abnormalities, and intellectual disability.

Management

There is no cure for aniridia, but management focuses on addressing the symptoms and preventing complications:

• Vision correction: Glasses or contact lenses may be prescribed to improve visual acuity.
• Surgical interventions: Procedures may be necessary to manage cataracts or glaucoma.
• Regular monitoring: Patients require regular follow-up with an ophthalmologist to monitor for complications such as glaucoma.

Prognosis

The prognosis for individuals with sporadic aniridia varies depending on the severity of the condition and the presence of associated complications. Early intervention and regular monitoring can help manage symptoms and improve quality of life.

Also see

• WAGR syndrome
• PAX6
• Glaucoma
• Cataract
• Nystagmus

External

• Age-Related Macular Degeneration

• Amblyopia (Lazy Eye)

• Anophthalmia and Microphthalmia

• Astigmatism

B

• Behçet's Disease* Bietti's Crystalline Dystrophy

• Blepharitis* Blepharospasm

C

• Cataracts

• Coloboma

• Color Blindness

• Corneal Conditions

D

• Diabetic Retinopathy

• Dry Eye

F

• Floaters

G

• Glaucoma

I

• Idiopathic Intracranial Hypertension

L

• Low Vision

M

• Macular Edema

• Macular Hole

• Macular Pucker

P

• Pink Eye

R

• Rare Diseases

• Refractive Errors

• Retinal Detachment

• Retinitis Pigmentosa

• Retinoblastoma

• Retinopathy of Prematurity

S

• Stargardt Disease

U

• Usher Syndrome

• Uveitis

V

• Vitreous Detachment