iris1(redirected from iris1 freckle)
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.
angle of iris1
see filtration angle.
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.
the iris is bowed forward by increased pressure in the posterior chamber and may adhere to the cornea.
short, threadlike projections from the minor arterial circle of the iris.
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.
an area of hyperpigmentation without hyperplasia of the melanocytes.
see heterochromia iridis.
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.
a vestigial iris; usually the ciliary body is normal. The lens is cataractous and may be displaced.
a benign melanotic tumor of the iris consisting of melanocytes.
protrusion of part of the iris through a perforation in the cornea or the sclera.