Coloboma

"Coloboma describes a situation where the patient has a portion of the structure of the eye lacking. This gap can occur in a range of areas and be large or small.

The most common form of gap is caused by an imperfect closure of a cleft, present in the womb but usually closed by birth date. This gap can occur in the eyelid, iris, lens, choroid or optic disc. In some cases other developmental flaws accompany it.

The effects of the condition can be mild or severe and this will depend upon the extent and location of the gap, or incomplete closure. The gap is usually at the bottom of the eye. Coloboma may occur in the iris/lens, choroid, macula or optic nerve.

A lens coloboma, if large, may also include flaws in the iris and choroid and slightly increase risk of retinal tearing. In severe cases, the eye may be reduced in size. This condition is called Microphthalmous, a condition that may arise without coloboma.

Coloboma of the iris may sometimes give the appearance of a keyhole in the pupil. Central vision may be affected and may reflect the extent, location and shape of the gap.

In some cases the problem may be accompanied by other problems which may be neurological or chromosomal. A few syndromes also include coloboma among the potential problems.

There is a specific combination of flaws identified by the acronym "CHARGE" which stands for:

C - Coloboma;
H - Heart defects;
A - Atresia of the choanae (blockage of the nasal passages);
R - Retarded growth and development;
G - Genital hypoplasia (undescended testes);
E - Ear anomalies.

CHARGE is a very rare problem and will receive specialist attention and treatment from an early age."