Knowra Aniridia Aniridia Aniridia is a rare eye disorder involving partial or complete absence of the iris, usually present from birth. It often results from variants in the PAX6 gene and can affect vision and other eye structures.
PAX6 : PAX6 is a gene that encodes a transcription factor essential to eye development. Variants in this gene cause many inherited cases of aniridia.
PAX6-related aniridia : PAX6-related aniridia is an inherited form caused by pathogenic variants affecting one copy of PAX6. It accounts for most familial cases and often affects both eyes.
Slit-lamp examination : Slit-lamp examination uses a focused light beam and microscope to inspect the front and internal structures of the eye. It helps clinicians assess iris remnants, the cornea, lens, and signs of glaucoma.
WAGR syndrome : WAGR syndrome is a rare genetic condition involving Wilms tumor, aniridia, genitourinary anomalies, and developmental delay. Aniridia with a PAX6-region deletion can be part of this syndrome.
Congenital aniridia : Congenital aniridia is aniridia present from birth, usually involving both eyes and often associated with other developmental eye abnormalities. It is the typical presentation, in contrast to rare acquired iris loss.
Iris : The iris is the colored, contractile tissue that regulates how much light enters the eye. Its partial or complete absence defines aniridia.
Iris hypoplasia : Iris hypoplasia is incomplete development of the iris, ranging from mild underdevelopment to near absence. The visible iris may be partly present rather than wholly absent.
Intraocular pressure : Intraocular pressure is the fluid pressure inside the eye. Regular measurement can detect glaucoma, a major later complication of aniridia.
Wilms tumor : Wilms tumor is a kidney cancer that primarily affects children. Its risk is elevated in WAGR syndrome, making systemic assessment important when that diagnosis is suspected.
Iris coloboma : Iris coloboma is a notch or keyhole-shaped defect caused by incomplete closure of the embryonic optic fissure. Unlike aniridia, it is usually a localized defect in an otherwise formed iris.
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