Fuch's Corneal Dystrophy

The cornea is the clear "window" in the front of the eye that allows light rays to enter the eye.

The cornea is composed of three layers – the outer epithelium (or "skin"), a middle area called stroma and a delicate, single celled inner lining called the endothelium. The corneal endothelium prevents water inside the eyeball from moving into and swelling the other layers of the cornea. The cells of the endothelium actively pump water from the cornea back into the eye. When the endothelium does not function normally, water will seep into the cornea and cause swelling. It is this swelling that causes clouding of the cornea and blurring vision. The more corneal swelling or "edema", the more severe the blurring. Eventually the epithelium also takes on water which results in pain and more severe vision impairment. Epithelial swelling changes the normal corneal curvature and causes a sight-limiting haze to develop. Epithelial swelling may also form small "blisters" on the corneal surface. When these "blisters" burst, it can be extremely painful.

We gradually lose endothelial cells as we age and these cells don't grow back. The remaining cells spread out to cover the empty spaces, trying to pump water from a larger area and become less efficient. Most people have enough endothelial cells throughout life to prevent corneal swelling.

Fuchs’ dystrophy (named after Dr. Fuchs) is an inherited disease that affects the endothelium and hinders its function and causes the cells to die faster than normal. It's a dominant gene and only one parent needs to be a carrier of the disease for an average of 50% of their children to inherit the disease.

Symptoms include:

• Hazy vision that is often most pronounced in the morning
• Fluctuating vision
• Glare when looking at lights
• Light sensitivity
• Sandy, gritty sensation
• Episodes of sharp, sometimes incapacitating pain

Fuch's usually doesn't cause problems until the person is 50-60 years old. There is no cure, but there are some medications that help. Once it gets bad enough a corneal transplant is performed.

This isn't a common condition, but it could become more common as it spreads through the population. Not everyone who carries the gene develops swelling and blurred vision.

Dale L. Edwards