A coloboma is a congenital malformation in which part of the eye does not form due to failure of fusion of embryonic structure called the intraocular fissure. This malformation can occur unilaterally or bilaterally and causes the eye to protrude anteriorly or posteriorly. There are many places a coloboma can occur; the iris, the lens, the choroid, the eyelid, the optic disc, or the retina. Colobomas are present at birth and usually affect 1 out of every 10,000 births. A coloboma can occur due to surgery, trauma or may be hereditary. If a child is diagnosed with a coloboma it is suggested that the parent have an eye exam because this condition can be present without any vision problems. The effect this condition has on vision depends on where in the eye the coloboma is located and how big the gap is. One example of a vision defect is a dislike to bright lights, which usually occurs in those with a coloboma in the iris. The key finding in children with this condition is a key-hole shaped pupil and may be diagnosed with the help of an ophthalmologist and MRI exam. A coloboma is typically identified on an MRI T2 weighted image as a hypodense protrusion of the orbital globe. Children affected by colobomas sometimes have an accompanying rare condition called CHARGE syndrome, which stand for; coloboma, heart defects, atresia of the choanae (problems with the nose passage), retarded growth and development, genital hypoplasia (undescended testicles), ear abnormalities. Currently there is no treatment for colobomas, except that the child will have help from a specialist to determine the effects and problems of the coloboma. Most children will be required to have eye exams every six months until the age of seven and then yearly after the age of seven, and will be prescribed sunglasses to help with light sensitivity.
Pediatric MRI T2 weighted image of a coloboma on the right side.
Key-hole shaped pupil in a child with a coloboma.
No comments:
Post a Comment