Fuchs Dystrophy

Fuchs dystrophy (said "fooks") is a slow, inherited wearing-out of the cells that keep the cornea clear. As they are lost, the cornea takes on water, swells, and turns hazy. It usually shows up after 50, affects both eyes, and progresses over many years. Many people with early Fuchs never need surgery. For those who do, a modern partial-thickness transplant restores clear vision.

Press Play to see what goes wrong and how it is treated.

The pump cells

The inner surface of the cornea is lined with a single layer of cells, the endothelium. Their job is to pump fluid out of the cornea continuously. That is what keeps it thin and transparent. These cells do not divide: you are born with a full set, lose them slowly through life, and normally have plenty in reserve.

In Fuchs dystrophy they are lost faster, and small bumps called guttae form where they were. When too few remain, the pump cannot keep up.

What it feels like

• Foggy or hazy vision on waking that clears over the morning. While the eyes are closed overnight nothing evaporates from the surface, so the cornea is at its most swollen when you get up.
• The fog lasting later into the day as the condition advances
• Glare and halos around lights, and poorer vision in dim light
• In advanced disease: constant blur, and painful blisters on the surface that can break

How it is followed

• At the slit lamp your doctor can see the guttae, often years before any symptoms.
• Corneal thickness is measured, since a swollen cornea is thicker.
• A cell count photographs the pump layer and counts the cells.

What helps

• Salt drops and ointment (sodium chloride 5%, sold as Muro 128) draw water out of the cornea. Drops are used during the day and ointment at bedtime. They help early swelling and morning fog. Both are pictured in the Eye Medication Reference.
• Lower eye pressure means less fluid is pushed into the cornea, so pressure is kept under control.
• A soft bandage contact lens eases the pain of surface blisters.

Fuchs and cataract surgery

Cataract surgery is hard on the pump cells in any eye, and a cornea with Fuchs has few to spare. This shapes the plan:

• Your doctor examines the cornea carefully before any cataract operation.
• Extra protective gel and gentler settings are used during surgery.
• In mild Fuchs, cataract surgery alone is often done, and the cornea is watched afterward.
• In more advanced Fuchs, cataract surgery and a corneal transplant are done together, or one soon after the other.

If you have Fuchs and are told you need cataract surgery, ask how your cornea affects the plan. See Cataract Surgery.

Surgery for Fuchs

When vision is affected through the day, the worn-out pump layer is replaced by a cornea specialist. Only that layer is transplanted, through a small incision, with no stitches in the cornea. The two versions are known as DMEK and DSAEK. Recovery is faster and rejection less common than with a full-thickness transplant. See Corneal Transplants.

If you have glaucoma

Some glaucoma drops (the carbonic anhydrase inhibitors, dorzolamide and brinzolamide) can add to corneal swelling in an eye with few pump cells, and glaucoma surgery can affect the cornea as well. Your doctor takes both conditions into account when choosing treatment.

Questions worth asking

• How advanced is my Fuchs dystrophy, and is it changing?
• Would salt drops help me?
• How does it affect my cataract surgery?
• When would you recommend a transplant?