Corneal Dystrophy, Posterior Polymorphous 4

Background and History: 

This is an inherited corneal dystrophy that can cause significant loss of vision and sometimes severe eye pain.

Clinical Correlations: 

A cloudiness of the cornea has been reported in infants but this is unusual.  In most cases the disease does not become symptomatic until adult life although some patients who carry the mutation responsible for this corneal disease remain asymptomatic throughout their lives.  In other individuals the cornea becomes swollen and cloudy resulting in blurry vision and eye pain.

Glaucoma has been reported in a few patients.

Genetics: 

A mutation in a specific gene is responsible for this corneal disease.  Pedigrees of these families show a vertical pattern of transmission characteristic of an autosomal dominant disorder.  A parent with this form of corneal dystrophy will transmit the mutation to each of his or her offspring with a 50% probability and on average half of the children will have this condition.

Diagnosis and Prognosis: 

Diagnosis is not possible in the newborn and if no family history of corneal disease is available a diagnostic gene test should be done.  In adults the history of progressive blurriness of vision should lead to a complete eye exam with special attention given to the cornea.  The cornea becomes thickened and appears cloudy.  A slit lamp examination is essential to visualization of the typical corneal changes.

Patients should always be evaluated for glaucoma.  The only treatment available is transplantation of a healthy cornea to replace the diseased one. 

Additional Information
Inheritance/Pedigree: 
Autosomal dominant