Polymorphous corneal dystrophy (PPMD) is a disorder that affects the Descemet membrane and the epithelium of the cornea, which make up part of the outer portion of the eye. This change in the layers can lead to decreased vision in the effected eyes.
The condition is normally slowly progressive or non-progressive, which means that the symptoms do not generally get worse over time. Usually, both eyes are affected, though they may be affected unequally. PPMD may be present at birth, but most patients are not diagnosed until 30-50 years of age, which is when symptoms often begin to appear.
PPMD is a genetic condition caused by mutations (changes) in the OVOL2 gene or the COL8A2 gene. We inherit our genes in pairs, one from each parent typically. For changes in either gene, PPMD is inherited in an autosomal dominant manner. Autosomal dominant means an individual only needs one copy of the changed gene or mutation that causes the condition. If one parent is a carrier for the mutated gene, children have a 50% chance of having the condition.
PPMD can be diagnosed by looking at the affected corneal layers of the eye, specially the Descemet membrane and the epithelium. Most individuals who have PPMD do not need treatment. In cases where they do, a cornea transplant may be performed, in which a doctor replaces the effected cornea.
If you or a family member has been diagnosed with polymorphous corneal dystrophy, talk with your doctor about the most current treatment options. Support groups are also good resources of support and information.
Description Last Updated: Sep 03, 2018