The cells that make up the inner layer of the cornea comprise the corneal endothelium. It consists of flat cells of regular polygonal shapes, which allow the transfer of fluids and nutrition, thus ensuring optimal hydration of the corneal stroma.
As we age, the density of endothelial cells decreases and so does the hydration of the corneal stroma. The endothelium may be affected by congenital degenerative defects, resulting in pathological changes in the cornea (Fuchs dystrophy and posterior polymorphous dystrophy). These diseases may occur in advanced age and can cause corneal edema or glaucoma.