Peters Anomaly
Patient Information
Characteristics
Background and History
This form of eye malformation is named for Albert Peters, a German ophthalmologist who first described it nearly 100 years ago. It usually occurs in only one eye. More recently, we have learned that when it occurs in both eyes this condition may be associated with other syndromes.
Clinical Correlations
The eye condition known as Peters anomaly consists of incomplete formation of the front part of the eye. In particular, the iris (the colored part of the eye) may be attached to the cornea (the clear part, or windshield of the eye) and this often leads to swelling of the cornea causing it to look cloudy and, of course, interfering with vision. There is considerable variation in the amount of eye damage. In some patients cutting the iris adhesions may be enough to allow some clearing of the corneal clouding. Sometimes the lens of the eye is attached as well and this can cause a cataract.
In many cases, the underlying defects lead to glaucoma which is the most serious threat to vision and is often difficult to treat.
Genetics
Inheritance
Isolated Peters anomaly usually occurs in an autosomal recessive pattern but autosomal dominant patterns have been reported as will. The recessive disorder may be caused by a mutation in several genes. The condition is likely the result of a disruption in some common metabolic pathway or pathways.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
Diagnosis and Prognosis
Your eye doctor can make this diagnosis only after a careful eye examination as various features such as glaucoma can be found in other conditions as well. The iris adhesions, if removed from the cornea, can lead to some clearing of the cloudiness but in other cases a corneal transplant is required. If a cataract is present, this can be surgically removed. The most difficult eye problem to treat is glaucoma and generally a pediatric glaucoma expert is the best specialist for this.
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