This 28-year-old female presents for a routine examination, which is normal except for a white snail track-like appearance on her posterior cornea. What do we see here?

Analysis
Here, we see posterior polymorphous corneal dystrophy (PPCD), which is a hereditary corneal dystrophy of the endothelium and Descemet's membrane. PPCD tends to occur bilaterally since it is hereditary, and it is often asymptomatic. The white track-like appearance is caused by endothelial cells adopting characteristics of epithelial cells.
In this 2-minute video featuring Dr. Ashley Brissette, assistant professor at Weill Cornell Medicine in New York, you will:
- Learn how to identify posterior polymorphous corneal dystrophy
- Review the pathophysiology of posterior polymorphous corneal dystrophy
- Understand why it is important to monitor patients with posterior polymorphous corneal dystrophy

Cornea Coach Tip
Patients with PPCD are at a higher risk of glaucoma due to migration of cells into the angle, and thus require monitoring of IOP and cup-to-disc ratio.
Not receiving our tips yet? Subscribe to receive them straight to your inbox.