A hole or defect in the parts of the eye is called coloboma. Most cases of coloboma are congenital, meaning the problem is present at birth. It is often marked by a keyhole-shaped pupil and may affect one or both eyes.
If coloboma affects a person’s iris, they may have a fairly good vision, whereas those with the problem in retina may have partial vision loss in specific parts which may devoid the person of reading, writing, and close-up work or play.
If there is a large retinal coloboma, the one which affects with optic nerve, can cause vision loss thajt cannot be completely corrected with glasses or contact lenses.
If a person has an isolated coloboma, they may have normal vision and no symptoms. Sometimes, they may have mild to severe vision impairment. How the affected person’s vision is affected depends on where the gap or gaps occur in the eye. Symptoms may include:
The cause of coloboma is known to be abnormal development of the eye during the third trimester of gestation. It is during this time that the interior structures of the eye are forming. When the fissure does not close completely, the defect occurs.
Environmental factors that affect early development, such as the exposure to alcohol and certain drugs during pregnancy, may increase the risk of coloboma.
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