This is the result of congenital malformation, with a portion of the eye failing to complete its growth and fuse together, so leaving a cleft. Different parts of the eye may be affected, including the lens, choroid and optic nerve, although the iris is most commonly involved giving a keyhole shaped pupil. Vision may or may not be affected depending on the part of the eye involved. These are not known but coloboma may be associated with a specific genetic disorder, otherwise it is an isolated sporadic event. Pre-natal diagnosis Fetoscopy or a high resolution ultrasound scan could provide details of the fetal eye in the second trimester.
Genetic counselling is available in cases of specific genetic disorder.
Contact a Family is a UK charity which helps families who care for children with any disability or special need. We are a main source of information about rare disorders and are able to assist affected adults as well as children. The CaF Directory Online contains details of many medical conditions and also patient support groups. The information in it is also provided as part of the NHS Direct Online service. Although great care has been taken in the compilation and preparation of this work to ensure accuracy, Contact a Family cannot accept responsibility for any errors or omissions.