Anophthalmia and microphthalmia

What is anophthalmia?

Anophthalmia is a rare condition that means that you are born with no visible eye. It causes sight loss or blindness, depending on whether one or both eyes are affected.

What is microphthalmia?

People with microphthalmia are born with very small eyes, below a certain size, that also have structural problems.

It also causes severe sight loss or blindness.

What causes anophthalmia and microphthalmia?

We don't always know what causes anophthalmia and microphthalmia. Several genes have been linked to anophthalmia and microphthalmia in recent years. But we don’t know exactly how they work or how they lead to eye defects. There are still more genes to find, but in some cases it may not be possible to find the exact cause.

Most people don’t have a family history of the conditions. A prenatal test may be available for families who are at risk.

Anophthalmia and microphthalmia can also be caused by taking certain medicines or exposure to certain chemicals during pregnancy. Microphthalmia can also be part of a syndrome that causes other issues in the body.

What are the signs and symptoms of anophthalmia or microphthalmia?

People with anophthalmia will be missing one or both eyes. People with microphthalmia will have one or both eyes that are visibly much smaller than usual.

People with these conditions will either be blind or have some degree of permanent sight loss in one or both eyes.

The disorders are often linked to other problems including brain malformations, cleft palate and cleft lip.

What are the treatments for anophthalmia and microphthalmia?

There is no cure for anophthalmia and microphthalmia. Treatment for these conditions is about reducing discomfort, and improving social well-being and facial appearance.

Children may be given long-term genetic counselling and may have surgery to expand the eye socket. A prosthetic eye (a ‘false eye’) may be fitted if it helps.

What research is there into anophthalmia and microphthalmia?

We don’t know exactly why anophthalmia and microphthalmia happen. This makes it hard to prevent. So we need to understand the causes before prevention or treatment can become possible. This involves studying how eyes form in the womb.

Discovering more of the genes with a link to these disorders will also mean that more families can have relevant genetic counselling to help them plan their families and their future.