In this disease, the endothelial cells in the cornea gradually deteriorate. As more endothelial cells are lost, the endothelium becomes less efficient at pumping water out of the stroma beneath it. This causes the cornea to swell and distort vision. Eventually, the epithelium also takes on water, resulting in pain and severe visual impairment. Epithelial swelling damages vision by changing the cornea's normal curvature, and causing a sight-impairing haze to appear in the tissue. Epithelial swelling also produces tiny blisters on the corneal surface. When these blisters burst, they are extremely painful.
At first, a person with Fuchs' dystrophy will awaken with blurred vision that will gradually clear during the day. This occurs because the cornea is normally thicker in the morning; it retains fluids during sleep that evaporate in the tear film while we are awake. As the disease worsens, this swelling will remain constant and reduce vision throughout the day.
Treatment is designed to reduce the swelling with drops, ointments, or soft contact lenses. A hair dryer, held at arm's length or directed across the face, may help dry out the epithelial blisters. This can be done two or three times a day. When the disease interferes with daily activities, a person may need to consider having a corneal transplant to restore sight.