Eyes can be missing, deformed, or incompletely developed at birth.
Birth defects, also called congenital anomalies, are physical abnormalities that occur before a baby is born. "Congenital" means "present at birth." (See also Introduction to Birth Defects of the Face, Bones, Joints, and Muscles.)
Birth defects of the eye include the following:
Hypertelorism: Widely spaced eyes, can occur in several congenital syndromes (a group of defects present at birth that occur together)
Hypotelorism: Closely spaced eyes
Coloboma: A missing piece of tissue in any part of the eye, such as the eyelid, iris, retina, or optic nerve of one or both eyes
Microphthalmia: A small eyeball (may affect one or both eyes)
Anophthalmia: Complete absence of the eyeball (can occur in more than 50 congenital syndromes)
Some of these birth defects may be caused by mutations in certain genes. Others may be caused by the mother's use of certain drugs or alcohol while pregnant or an infection she may have had while pregnant.
A child who has a birth defect of the eye often has other birth defects, particularly of the face or brain.
© Springer Science+Business Media
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
© Springer Science+Business Media
© Springer Science+Business Media
© Springer Science+Business Media
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
© Springer Science+Business Media
© Springer Science+Business Media
Diagnosis of Eye Defects
Before birth, ultrasonography of the fetus and sometimes a blood test
After birth, physical examination of the newborn
Genetic testing
Before birth, doctors may be able to identify some eye defects during an ultrasound and sometimes by doing amniocentesis or chorionic villus sampling to obtain a sample of DNA from the fetus to do genetic testing.
After birth, doctors can identify many eye defects during a physical examination.
Because abnormal genes may be involved in the formation of birth defects of the eye, affected babies should be evaluated by a geneticist. A geneticist is a doctor who specializes in genetics (the science of genes and how certain qualities or traits are passed from parents to offspring). Genetic testing of a sample of the baby's blood may be done to look for chromosome and gene abnormalities. This testing can help doctors determine whether a specific genetic disorder is the cause and rule out other causes. If there is a genetic disorder, families may benefit from genetic counseling.
Treatment
Birth defects of the eye are treated surgically using various surgical techniques.
