coloboma (redirected from Coloboma of optic nerve)

coloboma /col·o·bo·ma/ (kol″o-bo´mah) pl. colobomas, colobo´mata   [L.]

1. an absence or defect of tissue.

2. a defect of ocular tissue, due to failure of part of the fetal fissure to close; it may affect the choroid, ciliary body, eyelid, iris, lens, optic nerve, or retina.

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bridge coloboma  coloboma of the iris in which a strip of iris tissue bridges over the fissure.

Fuchs' coloboma  a small, crescent-shaped defect of the choroid at the lower edge of the optic disk.

coloboma lo´buli  fissure of the ear lobe.

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col·o·bo·ma (kl-bm)

n. pl. col·o·bo·mas or col·o·bo·ma·ta (-m-t)

An anomaly of the eye, usually a developmental defect, often resulting in some vision loss.

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coloboma

[kol′əbō′mə] pl. colobomas, colobomata

Etymology: Gk, koloboma, defect

a congenital or pathologic defect in the ocular tissue of the body, usually affecting the iris, ciliary body, or choroid by forming a cleft that extends inferiorly. Colobomas are usually the result of the failure of part of the fetal fissure to close. colobomatous, adj.

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coloboma

an apparent absence or defect of some ocular tissue, usually due to failure of a part of the fetal fissure to close; it may affect the choroid, ciliary body, eyelid (palpebral coloboma, coloboma palpebrale), iris (coloboma iridis), lens (coloboma lentis), optic nerve or retina (coloboma retinae). Colobomas of the choroid are common in cattle, and have been observed in miniature swine. Colobomas of the optic disk are an inherited defect in several breeds of cattle.

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atypical coloboma

on occurring at a location other than the fetal fissure.

iris coloboma

a full thickness defect in the iris. When it occurs at the base of the iris, it is called iridodiastasis.

optic nerve coloboma

part of the scleral ectasia syndrome in dogs; also seen in Basenji dogs and Charolais cattle.

typical coloboma

one occurring in or near to the fetal cleft.

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coloboma 

Congenital, pathological or operative anomaly in which a portion of the structure of the eye is lacking, e.g. coloboma of the choroid, coloboma of the eyelid, coloboma of the iris, coloboma of the lens, coloboma of the retina, etc. Typical colobomas result from defective closure of the embryonic fissure of the optic cup. Congenital iris colobomas are usually located inferiorly. They are often associated with Crouzon's syndrome (Fig. C13). Lid colobomas are commonly associated with Treacher-Collins syndrome. Coloboma of the optic disc is characterized by a glistening, white excavation, decentred inferiorly. It is sometimes confounded with glaucomatous cupping, especially when it is accompanied by a field defect. The condition is often associated with microphthalmia and several syndromes (e.g. Edward's syndrome, Patau's syndrome).

Fig. C13  Coloboma of the iris

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Patient discussion about Coloboma of optic nerve.

Q. My grandson 5mths has been dignosed with Coloboma HAs anyone had any experiences with this. He will be seen at Toronto Hospital for Sick Kids

A. Don't have it or a child with it, so I can't add from my own experience. However, here are several places in which you can find more information about this:

http://en.wikipedia.org/wiki/Coloboma
http://www.nlm.nih.gov/medlineplus/ency/article/003318.htm