Walsh & Hoyt: Structural Defects of the Iris

Congenital defects. Aniridia. Aniridia is a rare congenital abnormality in which the iris is partially hypoplastic or completely absent. Patients with aniridia initially may be thought to have fixed, dilated pupils until a more careful examination is performed. In almost all cases, histologic or gonioscopic examination reveals small remnants of iris tissue. The iris is only minimally developed, and the iris musculature usually is hypoplastic. Patients with aniridia often have photophobia, poor visual acuity, and other ocular defects, including glaucoma, cataracts, ectopia lentis, corneal opacification, ciliary body hypoplasia, optic nerve hypoplasia, foveal hypoplasia, strabismus, and nystagmus. The condition usually is bilateral, and two thirds of cases are inherited in autosomal-dominant fashion. Coloboma of the iris. Square pupils. Elliptic pupils. Scalloped pupils. Peninsula pupils. Ectopic (misplaced) pupils. Persistent pupillary membrane remnants. Polycoria and pseudopolycoria. Congenital miosis. Cogenital mydriasis. Congenital abnormalities of iris color. Acquired defects. Inflammation. Ischemia. Tumor. Trauma. Acute angle-closure glaucoma. Atrophy. Postoperative mydriasis.