Fuchs' Endothelial Corneal Dystrophy
A common adult-onset form of corneal dystrophy with autosomal dominant inheritance. The disorder is caused by mutation in the COL8A2 gene. In this disease, the endothelial cells (which line the back of the cornea, the clear part of the eye) gradually deteriorate. As more endothelial cells are lost, the endothelium becomes less efficient at pumping water out of the stroma (the main part of the cornea). This causes the cornea to swell and this distorts 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 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 vision.