Coloboma

Under a coloboma (from Greek κολοβωμα = the Mutilated ) refers to a congenital or acquired gap formation in the broadest sense. Most often, the term is used in ophthalmology, which is why this is called the ocular coloboma (hereinafter only the ocular coloboma is discussed ). In ophthalmology, the term refers to a congenital (partly inherited ) or acquired cleft of the iris ( iris ), the lens, eyelid, retina and / or choroid.

Pathogenesis

Congenital coloboma

The cause of a congenital cleft is in the embryonic development of the eye -founded and is associated with the inhibition malformations. Due to mismanagement under remains a complete circuit of the optic cup column after completion of intussusception ( ) of the optic vesicle to optic cup. Since the embryonic optic cup gap shows nasally downward, the congenital coloboma of the iris is usually also nasal, below. Depending on the severity are affected by the gap formation only one part or several parts of the eye.

Often the coloboma is associated ( scaled eyeball ) with a microphthalmia.

The malformation is often initiated by drugs or other chemical substances. This is especially thalidomide mentioned. There are also hereditary factors ( uaKatzenaugen syndrome, CHARGE syndrome, trisomy 3, Cohen syndrome ) and spontaneous occurrence of developmental disorder.

Acquired coloboma

Acquired colobomas are usually on external forces ( in case of accident or surgery ) due. This leads to a cleavage, for example of the eyelid or the iris.