Aniridia (Congenital Iris Absence)

Aniridia (literally absence of the iris) is more accurately a panocular disorder affecting iris, cornea, lens, anterior chamber angle, optic nerve, and retina due to mutations in the PAX6 gene on chromosome 11p13. Two-thirds of cases are familial autosomal dominant; one-third are sporadic. WAGR syndrome (Wilms tumor, Aniridia, Genitourinary anomalies, intellectual disability) results from contiguous deletion of PAX6 and WT1, requiring renal surveillance.

Foveal hypoplasia causes congenital nystagmus and reduced visual acuity (typically 20/100 to 20/200). Aniridic keratopathy, a progressive epithelial disorder due to limbal stem cell deficiency, develops in adolescence or adulthood with corneal pannus, neovascularization, and opacification. Glaucoma develops in 50-75% of patients, often in late childhood or adulthood, related to angle dysgenesis, progressive trabecular meshwork rotation, or ectropion uveae.

Cataract develops in approximately 50-85% of patients, typically anterior or posterior subcapsular. Other associations include keratoconus, ectopia lentis, optic nerve hypoplasia, and chorioretinal coloboma. Lifelong specialized care addresses refractive correction, photophobia, glaucoma management, ocular surface optimization, and preservation of vision through individualized intervention.