What is Coloboma
Anophthalmia and Microphthalmia are often used interchangeably. Microphthalmia is a disorder in which one or both eyes are abnormally small, while Anophthalmia is the absence of one or both eyes. These rare disorders develop during pregnancy and can be associated with other birth defects. A Colombola is a gap in part of the structure of the eye. This gap can be large or small and is normally in the bottom part of the eye. All of these conditions can result in the child being blind or partially sighted. Children who have a visual impairment that is due to a congenital condition sometimes have other problems such as learning difficulties or behaviour problems. Occasionally there are more severe problems or disorders. This is because the brain forms at the same time as the eyes, which are really an extension of the brain rather than separate organs.
Prosthetics - Prosthetic eyes are usually made from acrylic. Sometimes porcelain is used if there is an allergy to acrylic. If there is any vision at all in an eye then a prosthesis will not normally be fitted until the child reaches five years old. This is because if that eye is covered up for long periods the brain will cease to recognise the signals, causing a 'lazy eye'. It is also important to establish if there is any useful vision in the affected eye(s), which is most reliably done at a later age. After the age of five to seven years then the brain is able to compensate and no vision will be lost. As the child grows the prosthesis will need to be checked regularly for size, comfort and fit (usually two to three times a year). It also needs to be polished and checked for any damage such as sharp edges etc.
Causes - True Anophthalmia occurs in around 1 in 100,000 births. Microphthalmia and Coloboma occur in around 1 in 10,000 births. Around two thirds of these cases are believed to be genetic. The remaining are thought to be caused by environmental factors such as drugs, pesticides, radiation, toxins or viral causes. Some viruses that have been linked to these conditions are Toxiplasmosis, Rubella and certain strains of the flu virus. Research into the cause or causes of these distressing conditions has intensified over the past few years. One day the cause will be identified and hopefully lead to a significant reduction in the amount of children being born with these conditions.
The information contained here is intended as a guide for Anophthalmia, Microphthalmia and Coloboma. We hope that you find the contents useful and informative. All of this information has been put together by parents of children born with these conditions and has been gathered from various professional sources. As far as we can determine, its contents are true and accurate. Please remember that each child is different and this information should not be used to make a diagnosis. Any diagnosis should me made by a qualified ophthalmologist.
We gratefully acknowledge Dr Danny Morrison, Ophthalmologist, for his assistance in putting this information together.