In a healthy cornea, a single layer of cells, called endothelial cells and localized on the back surface of the cornea keeps the clarity of the cornea by pumping fluid back into the aqueous humor.
Congenital disease such as Fuchs dystrophy or trauma induced by cataract, glaucoma or any intra ocular surgery might lead to a decrease in the number of endothelial cells. When the number of cells becomes too low, fluid is not pumped out of the cornea anymore and this induce a corneal swelling and edema.
At an advanced stage, corneal edema can induce an important decrease in vision in addition to severe eye pain due to rupture of epithelial bullae (filled of fluid).
Symptomatic treatment includes hyperosmotic eye drops to reduce swelling (5% sodium chloride) and bandage contact lenses to reduce discomfort.
Curative treatment is surgical and aims to replace the damaged tissue. The most advanced type of surgical treatment is Descemet's membrane endothelial keratoplasty (DMEK).