Aniridia is a congenital ocular malformation characterized by the complete or partial absence of the iris. It can be isolated or part of a syndrome (isolated and syndromic aniridia; see these terms).
The annual incidence of isolated aniridia is estimated at 1/ 64,000- 1/ 96,000.
Isolated aniridia can occur in association with a range of other ocular anomalies including cataracts, glaucoma (usually occuring during adolescence), corneal pannus, optic nerve hypoplasia, absence of macular reflex, ectopia lentis, nystagmus, and photophobia, all of which generally result in poor vision. Syndromic aniridia is associated with other non ophthalmological anomalies, for instance: nephroblastoma (Wilms tumor), genitourinary abnormalities and intellectual deficit in the case of the WAGR syndrome (see this term), or other developmental anomalies in more rare syndromes.
Last update: March 2012