Anophthalmia is a medical term used to describe the absence of the globe and ocular tissue from the orbit. Anophthalmia and microphthalmia (small eyes) are used interchangeably since in most cases there are some remnants of either the globe or surrounding tissue. Anophthalmia / microphthalmia (A/M) may affect one eye with the other eye being normal, or both eyes, resulting in blindness.
Anophthalmia can be congenital (present at birth) or acquired later in life. Congenital anophthalmia can occur alone or along with other birth defects. Cases of anophthalmia may result from inherited genetic mutations, sporadic genetic mutations, chromosome abnormalities, prenatal environmental insult or unknown.
Growth and development of the face is usually dependent upon the presence of an average-sized eye within the orbit. Facial development occurs very rapidly in an infant and young child: about 90% of the orbital growth is complete by 5 years of age. if the orbit is empty, it will not grow properly. In turn, the child's face will not grow properly and this may lead to changes in the child's facial appearance.
Anophthalmia is very rare but the exact incidence is unknown. One report from a prospective study of 50,000 newborns found an incidence of microphthalmia of 0.22 per 1,000 live births.