An apparent absence or defect of some ocular tissue, usually due to failure of a part of the fetal tissue to close; it may affect the choroid, ciliary body, eyelids, iris, lens, optic nerve, or retina.
Notch or cleft in the pupil, iris, lens, retina, choroid, or optic nerve. Its location determines the degree of vision loss. There may be decreased acuity, photophobia, field loss, refractive errors, and poor depth perception.
describes people who are missing a portion of the structure of the eye. The human eye develops between the fourth and 15th week of pregnancy. As it starts to develop, a gap opens on the underside of each eye bud. This gap provides a way for the developing eye to be nourished. This gap, called the optic fissure, has to close before the eye is fully developed. Coloboma is the incomplete closer of the optic fissure.
A congenital problem with the eye that is related to a maldevelopment or underdevelopment of a part of the eye. It may involve the eyelid, or interior part of the eye (involving the choroid and occasionally the optic nerve).
This is a congenital defect where the inferior (bottom) part of the iris and/or retina may be missing. It is the result of an incomplete formation of the eye during the fetal stage of development. An iris can also happen due to an injury of the eye, or sometimes after eye surgery. An eye with an iris coloboma has a "keyhole" shaped pupil.
Cleft, usually due to incomplete embryologic development in utero. An iris coloboma is the most common eye coloboma; the pupil will often look like a keyhole or upside-down pear. Colobomas can also affect other eye structures, such as the eyelid, retina and optic nerve; only iris and eyelid colobomas are visible with the naked eye. Additional symptoms such as poor vision may occur, but are not readily apparent from a parent's perspective.
A coloboma (also part of the rare Cat Eye syndrome) is the term used to describe a hole in one of the structures of the eye, such as the lens, eyelid, iris, retina, choroid or optic disc. The hole is present from birth and can be caused when a gap between two structures in the eye, which is present early in development in the womb, fails to close up completely before a child is born. A coloboma can occur in one or both eyes.