What are the causes? The condition is likely to occur because the delicate sequence of early developmental steps to form the eye is disrupted in some way. This could be because of changes in genes or through external factors acting on the developmental processes during pregnancy or a combination of the two. Anophthalmia and microphthalmia have been related to some illnesses during pregnancy such as rubella and chicken pox. They have also been linked to some drugs taken during pregnancy, including recreational drugs and thalidomide. Over the last few years, several genes have been described as important in anophthalmia and microphthalmia. These eye development genes include SOX2, OTX2, BMP4, RX, SHH (sonic hedgehog), CHX10 (also called VSX2), BCOR, BMP7, RAB3GAP, FOXE3, PITX2, FOXC1, MITF, HCCS, CHD7, CRYBA4, GDF6, LRP6, STRA6 and PAX6. Whilst many of these genes have only been described so far in association with a few families worldwide, SOX2 seems to be important in around 10-15 per cent of children with anophthalmia. How is it treated? It is not possible to restore sight to a baby with anophthalmia affecting both eyes. However artificial eyes, usually made of acrylic and painted to look like real eyes, are used to help with the cosmetic appearance. Treatment is beneficial for these babies from a very early age, as the eye socket does not receive the correct signals to grow properly. Therefore, it is important that babies born without an eye or with a very small eye are referred for assessment at a specialist centre as soon as possible. In this way, the socket can be stimulated to grow using soft expanders or conformers as early as possible, and then artificial eyes can be fitted to improve cosmetic appearances. Inheritance patterns and prenatal diagnosis Inheritance patternsAlthough many cases of anophthalmia or microphthalmia appear to be isolated cases within a family, this may be due to a new change in a gene that could be passed on to future generations, or the variable expression of a change in a gene that is inherited. Therefore, it is very important for families to obtain genetic counselling. Prenatal diagnosisIn families where a causative gene has been identified, prenatal testing may be possible. Although it may occasionally be possible to diagnose anophthalmia on an ultrasound scan after six months of pregnancy, it is very difficult to diagnose microphthalmia or related eye anomalies. Is there support? MACS (Microphthalmia, Anophthalmia and Coloboma Support) Helpline: 0800 169 8088Email: email@example.comWebsite: macs.org.uk The Society is a Registered Charity in England and Wales No.1161897. It provides information and support for the families of children born without eyes or with underdeveloped eyes. The Society offers financial assistance, respite holidays, practical advice around health and benefits, and has a network of regional support groups. Group details last updated August 2017.