
What is aniridia?
12 October 2023
Aniridia is a congenital eye condition in which the iris is missing, or the iris is underdeveloped. The iris is not only the part of the eye that gives color, but it also regulates the amount of light that enters the eye, thus controlling the amount of light that reaches the retina. In the absence or limited presence of the iris, those affected by aniridia may experience sensitivity to light and difficulty adjusting to changes in lighting.
Causes and genetics
Aniridia can be caused by inherited genetic mutations or, in some cases, it can be sporadic (occur without a family history). Most cases of aniridia are associated with mutations in the PAX6 gene, which plays a crucial role in the development of the eye and other sensory organs. These mutations affect the formation and development of the iris, as well as other ocular structures. The inheritance of aniridia follows an autosomal dominant pattern, meaning that a single parent passing on the mutation can result in the child having the condition.
Symptoms and diagnosis
Aside from missing or underdeveloped irises, symptoms of aniridia can include reduced vision, photophobia (sensitivity to light), nystagmus (uncontrollable eye movements), and in some cases, additional eye development problems. Diagnosis is usually made during childhood, through comprehensive ophthalmological examinations and genetic testing to confirm the presence of mutations in the PAX6 gene.
Treatments and management
While there is no cure for aniridia, there are several strategies to help people manage and mitigate their symptoms. These may include:
- Contact lenses and special glasses: Help reduce sensitivity to light and improve vision.
- Surgery: In some cases, surgical procedures may be performed to correct additional problems associated with aniridia, such as glaucoma.