Fuchs' Endothelial Dystrophy

What is Fuchs dystrophy?

Fuchs’ endothelial dystrophy is a progressive condition affecting the cornea's innermost layer, known as the endothelium. This layer plays a vital role in pumping excess fluid out of the cornea to maintain its transparency.

In Fuchs’ dystrophy, the endothelial cells gradually deteriorate over time, leading to fluid accumulation, swelling (oedema), and a loss of corneal clarity. This results in blurred vision and other symptoms that can significantly impact quality of life. The condition is often hereditary and typically progresses slowly over several years.

What are the symptoms?

The symptoms of Fuchs’ dystrophy often fluctuate, typically appearing most prominent first thing in the morning. Common signs include:

• Blurred or misty vision on waking: This is a hallmark of the condition; vision is often cloudiest in the morning but may improve slightly throughout the day as the excess fluid evaporates.
• Halos and glare: You may notice "halos" or starbursts around bright lights, which can make driving at night particularly challenging.
• Increased sensitivity to light (photophobia): Bright environments or sunlight may become increasingly uncomfortable or dazzling.
• Foreign body sensation: In advanced stages, small fluid-filled blisters (bullae) can form on the corneal surface. If these rupture, they cause a gritty sensation or acute discomfort, as if something is in your eye.
• Gradual decline in visual clarity: Over time, the loss of transparency can become permanent if the underlying swelling is not managed.

What are the causes?

While the exact trigger for the cellular decline in Fuchs’ dystrophy is still being researched, several key factors are known to contribute to its development:

• Genetic Factors: The condition is frequently hereditary. If you have close family members affected by the disease, you are at a higher risk of developing it yourself.‍
• Age: Although early signs can be detected during a routine eye exam in younger years, symptoms typically become noticeable after the age of 50.‍
• Hormonal Factors: Statistically, the condition is slightly more prevalent in women than in men.‍
• Environmental Stress: Factors such as oxidative stress (caused by prolonged UV exposure and smoking) and chronic intraocular inflammation may accelerate the deterioration of the endothelial cells.

What are the treatments?

Treatment for Fuchs’ dystrophy is tailored to the severity of your symptoms and the clinical stage of the condition.

Medical treatments

• Hypertonic eye drops: These specialised drops (sodium chloride) help reduce oedema by drawing excess fluid out of the cornea through osmosis.‍
• Aiding evaporation: Using a fan or a hairdryer on a cool/lukewarm setting at arm's length can help accelerate the evaporation of excess fluid on the corneal surface upon waking.‍
• Therapeutic contact lenses: In advanced cases where fluid-filled blisters (bullae) have formed, "bandage" lenses can be used to protect the surface and alleviate pain.

Surgical treatments

When medical management is no longer sufficient, surgical intervention, specifically a corneal transplant, is the standard of care. Modern techniques now allow surgeons to replace only the damaged inner layer rather than the entire cornea.

• DMEK (Descemet Membrane Endothelial Keratoplasty): This advanced technique involves replacing the failing endothelium and its Descemet membrane with an ultra-thin graft (typically 10 to 15 microns). DMEK is currently the gold standard due to its superior visual outcomes and the lowest risk of graft rejection.‍
• DSAEK (Descemet Stripping Automated Endothelial Keratoplasty): A similar endothelial graft option. While the graft is slightly thicker than in DMEK, it remains a highly effective and widely used procedure for restoring corneal clarity.
• DSO (Descemet Stripping Only): Also known as Descemetorhexis without Endothelial Keratoplasty (DWEK), this is a newer, "graft-free" approach. The surgeon removes the central damaged part of the membrane, allowing the patient’s own healthy peripheral cells to migrate inwards. This eliminates the risk of rejection but is typically only suitable for patients with specific types of Fuchs’ dystrophy.‍
• Penetrating Keratoplasty (PKP): This is a full-thickness corneal transplant. It may be necessary in very advanced cases where long-term swelling has caused permanent scarring across all layers of the cornea.

Endothelial transplantation (DMEK/DSAEK), when performed at the appropriate stage, can restore clear vision and significantly improve a patient's quality of life.

It is important to note that prolonged oedema can lead to irreversible corneal scarring. If this occurs, a full-thickness transplant (PKP) becomes the only option to restore sight.

Regular follow-up with an ophthalmologist is essential to monitor the progression of the condition and ensure that surgical intervention is timed correctly for the best possible outcome.