Fuchs Endothelial Dystrophy

Corneal pump cell failure causing morning blur

Overview

Fuchs endothelial corneal dystrophy is a progressive disease of the corneal endothelium, the single layer of cells on the inner surface of the cornea that pumps fluid out of the corneal tissue to keep it clear. In Fuchs dystrophy these cells are gradually lost and small excrescences called guttae form on the underlying Descemet membrane. As pump function fails, the cornea swells, causing blurred vision and glare that are typically worst on waking and improve during the day as fluid evaporates from the surface. Advanced disease can produce painful epithelial blisters. It is more common in women and usually becomes symptomatic in middle or later adult life. A trinucleotide repeat expansion in the TCF4 gene accounts for many cases, while COL8A2 variants cause a rarer early onset form. It was first described by the Austrian ophthalmologist Ernst Fuchs in 1910. Definitive treatment is endothelial keratoplasty, DSAEK or DMEK, in which only the diseased inner layer of the cornea is replaced, and Fuchs dystrophy is one of the leading indications for corneal transplantation.