Endothelial insufficiency – Fuchs' dystrophy
Endothelial insufficiency, also known as Fuchs' dystrophy or cornea guttata, is a dysfunction of the innermost layer of the cornea (the transparent layer on the surface of the eye). This layer normally acts as a "pump," regulating corneal hydration. In endothelial insufficiency, fluid accumulates within the cornea, causing edema (swelling), thickening, and a loss of corneal transparency. This can lead to glare, blurred or hazy vision, and eye discomfort. Treatment involves absorbent eye drops, monitoring, and, if necessary, a partial corneal transplant (DMEK).
What is endothelial insufficiency?
Endothelial insufficiency occurs when the innermost layer of the cornea, called the endothelium, is no longer able to perform its role in regulating corneal hydration.
Endothelial dysfunction may be of degenerative origin (Fuchs' dystrophy) or traumatic origin during cataract surgery (endothelial decompensation of pseudophakic).
Fuchs' dystrophy typically affects both eyes and can lead to a gradual deterioration of your vision over the years. It usually develops in your 30s or 40s, but many people with Fuchs' dystrophy don't develop symptoms until they are 50 or 60.
The main aggravating factor of the dystrophy is cataract surgery, because the ultrasound delivered by the handpiece (cataract suction device) generates increased loss of endothelial cells.
Symptoms
Endothelial insufficiency often develops gradually. However, symptoms can appear suddenly after cataract surgery.
In the early stage – You may notice few or no symptoms.
Your vision may be blurry or hazy upon waking, for a few minutes to a few hours, but improves during the day.
This is because your eyes remain moist when they are closed during sleep. But when you are awake, your cornea dries out partly through evaporation.
In the advanced stage – Too much fluid accumulates during sleep and too little is absorbed during the day. You may experience:
Blurry or cloudy vision that is permanent and does not improve throughout the day.
Pain upon waking – Small blisters can form on the cornea, they grow larger and eventually burst, causing intense eye pain.
A sensation of sand or a foreign object.
Photophobia – Increased sensitivity to bright light
Your eye problems worsen in humid areas.
When to consult a doctor?
If you experience any of these symptoms, and especially if they worsen over time, consult an ophthalmologist specializing in the cornea.
He will be able to confirm the diagnosis, carry out the assessment, follow up and, if necessary, provide treatment.
Causes
The cells lining the inside of the cornea (endothelial cells) help maintain normal hydration levels within the cornea. This moisture regulation prevents the cornea from swelling.
In Fuchs' dystrophy, endothelial cells gradually die or malfunction, leading to fluid buildup (edema) in the cornea.
This causes thickening of the cornea and blurred vision.
Risk factors
The following factors increase your risk of developing Fuchs' dystrophy:
Sex – Fuchs' dystrophy is more common in women than in men.
Genetics – Fuchs' dystrophy is usually hereditary. The genetic basis of the disease is complex. Family members may be affected to varying degrees or not at all.
Age – Although there is a rare early-onset type of Fuchs' dystrophy that manifests in childhood, the disease usually begins in the thirties and forties, and symptoms develop thereafter.
Cataract surgery – Surgery results in a sudden loss of endothelial cells due to the energy used to aspirate the cataract near the endothelium. Patients with Fuchs' dystrophy often experience slower visual recovery and sometimes a worsening of symptoms after surgery.
Diagnosis
The diagnosis of Fuchs' dystrophy is most often clinical. The ophthalmologist notices, using a slit lamp (tabletop microscope), a granular appearance on the posterior surface of the cornea.
He will then assess the impact and severity of the condition by carrying out two examinations:
Pachymetry – This is a measurement of the thickness of the cornea, in order to assess the size of the edema.
Specular microscopy – The examination is performed on a special device that allows for microscopic imaging of the endothelial cells. This makes it possible to count the remaining cells and analyze their density and shape.
Treatment
There is no treatment to regenerate endothelial cells and therefore no cure for Fuchs' dystrophy. However, it is possible to control certain environmental factors and use eye drops to reduce swelling.
Early stage – Medical treatment
Eye drops – Hypertonic eye drops (rich in electrolytes) help absorb corneal edema upon waking in the morning. Treatments available in France are called ODM5® and Osmodrop®. Three drops should be instilled at 10-minute intervals upon waking in the morning.
Environment – Dry environments should be preferred to promote the reduction of corneal edema through evaporation.
Advanced stage – Corneal transplant surgery
In cases of persistently impaired vision, severe corneal edema, or corneal scarring, a transplant may be indicated:
Endothelial keratoplasty (DMEK) – Only the endothelial cell layer from a healthy donor is transplanted into your cornea. This is the most frequently performed transplant in the world.
Total corneal transplant (penetrating keratoplasty) – Your entire cornea is replaced with that of a healthy donor. This surgery is primarily indicated in cases of scarring or failure of a previous DMEK procedure.
Complications
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Cornea guttata is a disease that most often worsens gradually. However, without treatment, the cornea can become completely opaque, leading to blindness!