Aniridia is an uncommon panocular syndrome in which the most dramatic manifestation is partial or nearly complete absence of the iris (Fig 4-9). Aniridia has been linked to the loss of 1 allele of the PAX6 gene, a transcription factor that is important for the development and function of the cornea, lens, and retina. Associated findings include corneal pannus and epitheliopathy, glaucoma, foveal and optic nerve hypoplasia, and nystagmus. Aniridia is almost always bilateral. Two-thirds of cases are familial; one-third of cases are sporadic. Sporadic cases of aniridia are associated with a high incidence of Wilms tumor and the WAGR complex (Wilms tumor, aniridia, genitourinary malformations, and mental retardation).
Anterior or posterior polar lens opacities may be present at birth in patients with aniridia. Cortical, subcapsular, or lamellar opacities develop in 50%–85% of patients within the first 2 decades of life. The lens opacities may progress, further impairing vision. Poor zonular integrity and ectopia lentis have also been reported in patients with aniridia.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.