Anophthalmia

Synonyms and Related Keywords: Anophthalmos and microphthalmos, small eye syndrome

Overview
Anophthalmia, also known as anophthalmos (Greek: ανόφθαλμος, "without eye"), is the congenital absence of one or both eyes.

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.

Prevalence
True or primary anophthalmos is very rare. Only when there is complete absence of the ocular tissue within the orbit can the diagnosis of true anophthalmos be made. Extreme microphthalmos is seen more commonly. In this condition, a very small globe is present within the orbital soft tissue, which is not visible on initial examination.

There are three classifications for this condition.


 * Primary anophthalmia is a complete absence of eye tissue due to a failure of the part of the brain that forms the eye.
 * Secondary anophthalmia the eye starts to develop and for some reason stops, leaving the infant with only residual eye tissue or extremely tiny eyes which can only be seen under close examination.
 * Degenerative anophthalmia the eye started to form and, for some reason, degenerated. One reason for this occurring could be a lack of blood supply to the eye.

Causes
Anophthalmia and microphthalmia may occur secondary to the arrest of development of the eye at various stages of growth of the optic vesicle. It is important to recognize microphthalmia because the development of the orbital region, as well as the lids and fornices, is dependent on the presence of a normal-sized eye in utero.

Treatments
There is no treatment for severe anophthalmia or microphthalmia that will create a new eye or restore vision. However, some less severe forms of microphthalmia may benefit from medical or surgical treatments. In almost all cases improvements to a child's appearance are possible.

Children can be fitted for a prosthetic (artificial) eye for cosmetic purposes and to promote socket growth. A newborn with anophthalmia or microphthalmia will need to visit several eye care professionals, including those who specialize in pediatrics, vitreoretinal disease, orbital and oculoplastic surgery, ophthalmic genetics, and prosthetic devices for the eye. Each specialist can provide information and possible treatments resulting in the best care for the child and family.

The specialist in prosthetic diseases for the eye will make conformers, plastic structures that help support the face and encourage the eye socket to grow. As the face develops, new conformers will need to be made. A child with anophthalmia may also need to use expanders in addition to conformers to further enlarge the eye socket. Once the face is fully developed, prosthetic eyes can be made and placed. Prosthetic eyes will not restore vision.

How do conformers and prosthetic eyes look?
A painted prosthesis that looks like a normal eye is usually fitted between ages one and two. Until then, clear conformers are used. When the conformers are in place the eye socket will look black. These conformers are not painted to look like a normal eye because they are changed too frequently. Every few weeks a child will progress to a larger size conformer until about two years of age. If a child needs to wear conformers after age two, the conformers will be painted like a regular prosthesis, giving the appearance of a normal but smaller eye. The average child will need three to four new painted prostheses before the age of 10.

How is microphthalmia managed if there is residual vision in the eye?
Children with microphthalmia may have some residual vision (limited sight). In these cases, the good eye can be patched to strengthen vision in the microphthalmic eye. A prosthesis can be made to cap the microphthalmic eye to help with cosmetic appearance, while preserving the remaining sight.