iris1 (redirected from iris1 nevus)

iris¹

pl. irides [Gr.] the disk-like, centrally perforated, pigmented membrane behind the cornea; the most anterior portion of the vascular tunic of the eye, it is made up of a flat band of circular muscular fibers surrounding the pupil, a thin layer of radial muscle fibers by which the pupil is dilated, and, posteriorly, two layers of pigmented epithelial cells. See also iridial, pupil.

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angle of iris1

see filtration angle.

iris1 annulus

the inner, smooth, narrow section of iris is the minor iridial annulus; the wider, outer, plicated zone, the major iridial annulus.

Basenji mesodermal iris1 defect

see persistent pupillary membrane.

iris1 bombé

the iris is bowed forward by increased pressure in the posterior chamber and may adhere to the cornea.

Iris bombé. By permission from Slatter D, Textbook of Small Animal Surgery, Saunders, 2002

iris1 collarette

short, threadlike projections from the minor arterial circle of the iris.

iris1 cyst

may be congenital or developmental, following injury or inflammation. The cysts may detach and float free in the anterior or posterior chamber. They occur rarely in dogs and cats.

iris1 freckle

an area of hyperpigmentation without hyperplasia of the melanocytes.

iris1 heterochromia

see heterochromia iridis.

iris1 hypopigmentation

may be unilateral—called heterochromia. The structures of the iris are normal, as is the rest of the eye, except for the tapetum, which may be hypoplastic.

iris1 hypoplasia

a vestigial iris; usually the ciliary body is normal. The lens is cataractous and may be displaced.

iris1 inflammation

see iritis.

iris1 nevus

a benign melanotic tumor of the iris consisting of melanocytes.

iris1 prolapse

protrusion of part of the iris through a perforation in the cornea or the sclera.