Fuchs dystrophy is an inherited condition that affects the delicate inner layer, or the endothelium, of the cornea. In a normal function eye, the endothelium functions as a pump mechanism, constantly removing fluids from the cornea to maintain its clarity. As the dystrophy progresses, endothelial cells gradually deteriorate without any apparent reason. Once lost, the endothelial cells do not grow back, but instead spread out to fill the empty spaces. As more endothelial cells are lost over the years, the endothelium becomes less efficient at pumping water out of the stroma. This causes corneal clouding, swelling and eventually, reduced 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 will also produce tiny blisters on the corneal surface. When these blisters burst, they are extremely painful.
The inheritance of Fuchs dystrophy is autosomal dominant with genetic and environmental modifiers such as an increased prevalence in the elderly and in females. It is a disease that usually affects both eyes and is slightly more common in women than in men. Although doctors can often see early signs of Fuchs dystrophy in people in their 30s and 40s, the disease rarely affects vision until people reach their 50s and 60s. Endothelial cell loss may be aggravated or accelerated by intraocular trauma or surgery. This is common following cataract surgery or other types of ocular surgery.
In the early stages, Fuchs patients notice glare and light sensitivity. As the dystrophy progresses, a person 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.
Fuchs Dystrophy cannot be cured. With certain medications, however, blurred vision resulting from the corneal swelling can be controlled. When treating the disease, doctors will try first to reduce the swelling with salt solutions such as sodium chloride drops or ointments. This is done in order to draw fluid from the cornea and reduce swelling. They also may instruct a person to use a hair dryer, held at arm’s length, and blowing air into the face with the eye closed. This technique draws moisture from the cornea, and dries out the epithelial blisters, thus temporarily decreasing the swelling and improving the vision. 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, also known as a penetrating keratoplasty (PK), in order to restore their sight. New surgical modalities such as Descemet’s stripping endothelial keratoplasty (DSEK) are gaining popularity in the treatment of Fuchs Dystrophy. DSEK avoids the surgical complications of PK such as wound dehiscence and infections, and high postoperative astigmatism. Recently, DSEK has become the dominant procedure because it is technically much easier for the surgeon in comparison to alternative surgical procedures. The short-term success rate of corneal transplantation is quite good for people with Fuchs Dystrophy. However, some studies suggest that the long-term survival of the new cornea can be a problem.