Corneal dystrophy - symptoms, causes, treatment

What is corneal dystrophy?

Corneal dystrophy is a group of inherited conditions that affect the cornea - the transparent outer layer of the eye. Although corneal dystrophy can have different forms, they share one common denominator: degenerative changes that affect vision. As the disease progresses, people with corneal dystrophy may experience decreased visual acuity, photophobia, eye pain and even vision loss. Understanding the disease is crucial for early diagnosis and appropriate therapeutic interventions.

Corneal dystrophy is a genetic disease, meaning it is passed down from generation to generation. It occurs when mutated genes affect the normal functioning of corneal cells. Unlike many other eye diseases, corneal dystrophy is not associated with trauma, infection or external factors such as UV radiation. Changes in the cornea can affect different layers of the cornea: outer, middle or inner, leading to different types of dystrophy.

One of the most common types of dystrophy is Fuchs' dystrophy, which attacks the inner layer of the cornea - the endothelium. Another type is macular dystrophy, which causes changes in the central part of the cornea, as well as reticular dystrophy, leading to characteristic reticular deposits.

What are the causes of corneal dystrophy?

As already mentioned, corneal dystrophy has a genetic basis. It is an inherited disease, passed on in families, often in an autosomal dominant or recessive manner. Mutations in specific genes responsible for the structure and function of the cornea lead to abnormal protein production, resulting in the accumulation of abnormal substances in the corneal tissue. As a result, the cornea loses its transparency and elasticity, leading to clouding and impaired vision.

It should be remembered that corneal dystrophy is not caused by trauma or infection. For this reason, prophylaxis in the form of avoiding external factors is not applicable in preventing this disease. However, early diagnosis can help to slow the progression of the disease.

Symptoms of corneal dystrophy

Symptoms of corneal dystrophy depend on the type of disease and its severity. In the initial stage, many people may not experience any symptoms and changes may only be visible during a routine eye examination. As the disease progresses, symptoms may include:

• Misty or blurred vision - This is one of the most common symptoms of corneal dystrophy. The cornea becomes cloudy, making it difficult to see clearly.
• Photophobia – hypersensitivity to light może powodować dyskomfort, zwłaszcza w jasnym otoczeniu.
• Eye pain – w zaawansowanych przypadkach choroby, zwłaszcza przy dystrofii Fuchsa, ból może być wynikiem pęknięcia nabłonka rogówki.
• Corneal opacity - as the disease progresses, visible changes such as opacity or white deposits may appear on the cornea.
• Discomfort and a feeling of sand in the eye.

In some cases, such as Fuchs' dystrophy, symptoms are particularly worse in the morning when the eyes are dry. Early diagnosis and regular visits to the ophthalmologist can help manage these symptoms.

How to diagnose corneal dystrophy?

Diagnosing corneal dystrophy is crucial for early detection and effective treatment. As part of the diagnosis, the ophthalmologist can perform a number of tests:

• Slit-lamp examination - allows the cornea to be viewed in detail and its transparency and the presence of deposits to be assessed.
• Pachymetry - corneal thickness measurement, which is particularly important in Fuchs' dystrophy, where the cornea is thickened.
• Corneal topography - an examination that maps the shape of the cornea and helps identify abnormalities in its structure.
• Speculative microscopy - examination of corneal endothelial cells, which can help assess their condition in Fuchs' dystrophy.

In some cases, the ophthalmologist may recommend genetic testing, especially if the disease runs in the family. Genetic testing can help confirm the diagnosis and determine whether other family members are at risk of developing dystrophy.

Treatment of corneal dystrophy

Treatment of corneal dystrophy depends on the type of dystrophy and the severity of the disease. In milder cases, symptoms can be controlled with conservative treatment:

• Moisturising drops - used to relieve dryness and discomfort in the eye.
• Anti-inflammatory drops - can be used in cases where the dystrophy causes inflammation.
• Contact lens fitting - Specialised lenses can help improve visual acuity in cases of small corneal lesions.

In more advanced cases, such as Fuchs' dystrophy or reticular dystrophy, surgical treatment may be necessary:

• Phototherapeutic keratectomy (PTK) - a laser procedure used to remove superficial corneal lesions. It is effective in the treatment of some types of corneal dystrophy.
• Corneal transplantation - In cases where the lesions are advanced and significantly impair vision, a corneal transplant may be the only solution. This may be a full-thickness graft (penetrating keratoplasty) or a layered graft (DMEK, DSEK).

How to live with corneal dystrophy?

Living with corneal dystrophy may require some adjustments, especially if the disease affects daily functioning. Here are some tips on how to cope with the disease:

• Regular visits to the ophthalmologist - Even if the symptoms are mild, regular examinations make it possible to monitor the progression of the disease and to react quickly to any changes.
• Avoiding overexposure to bright light - Wearing sunglasses can help to manage photosensitivity.
• Eye protection - people with corneal dystrophy should avoid trauma to the eye, which can worsen the condition of the cornea.
• Healthy diet - Although corneal dystrophy is genetic, a healthy diet rich in vitamins A, C and E and antioxidants can support overall eye health.
• Psychological support - Corneal dystrophy can affect quality of life, so it is important that patients have access to support, both from specialists and loved ones.

A few words about Fuchs' dystrophy and Cogan's dystrophy

Fuchs' dystrophy

Fuchs' dystrophy is one of the most common inherited conditions of the cornea, which affects the inner layer of the cornea, called the endothelium. The endothelium plays a key role in maintaining the transparency of the cornea by removing excess fluid from its tissue. In Fuchs' dystrophy, endothelial cells gradually degenerate, leading to a weakening of this function, resulting in corneal fluid accumulation and swelling. The cornea becomes increasingly cloudy, leading to decreased vision.

Symptoms of Fuchs' dystrophy:

• Zamglone widzenie, szczególnie rano - during the day, vision may improve as corneal fluids partially evaporate.
• Photophobia - patients become hypersensitive to light.
• Eye pain - In more advanced cases, when epithelial rupture occurs, patients may experience pain.
• Thickening of the cornea - The cornea becomes thicker due to fluid accumulation, which can lead to further deterioration of vision.

Fuchs' dystrophy most commonly develops after the age of 50, although the first endothelial changes may be evident earlier. The disease affects women more often than men.

Treatment of Fuchs' dystrophy:

In milder cases of Fuchs' dystrophy, the following are used moisturising drops and medicines to dry the cornea. In advanced cases, when the patient loses visual acuity significantly, it may be necessary to perform a corneal transplantation (usually a layered graft, such as DMEK or DSEK), which involves replacing the damaged endothelial layer with healthy tissue.

Cogan's dystrophy

Cogan's dystrophy is a much rarer disease of the cornea, classified as an epithelial dystrophy. It affects the superficial layer of the cornea - the epithelium - and is characterised by changes in the nature of irregular protein deposits on the corneal surface. It is also often referred to as map-point (epithelial) dystrophy, as corneal lesions can take the form of maps, dots or episodes.

In Cogan's dystrophy, abnormal exfoliation of the corneal epithelial cells occurs, leading to a weakening of the connection between this layer and the other layers of the cornea. This disease can cause recurrent damage to the corneal surface, which affects the patient's comfort.

Symptoms of Cogan's dystrophy:

• Blurred vision - resulting from irregularities in corneal shape and opacity.
• Photophobia - hypersensitivity to light.
• Discomfort or pain in the eye - associated with damage to the corneal epithelium.
• Uczucie ciała obcego w oku - resulting from irregularities of the corneal surface.

Cogan's dystrophy can cause episodic visual impairment and discomfort, particularly with dry air or high visual effort. The condition usually develops in early adulthood and is not associated with other systemic conditions.

Treatment of Cogan's dystrophy:

The main treatment for Cogan's dystrophy is moisturising drops to relieve discomfort and dry eyes. For more severe corneal damage, laser treatments may be required, such as phototherapeutic keratectomy (PTK), to remove irregularities of the corneal surface. It is important that the patient is regularly monitored by an ophthalmologist to control the progression of the disease.

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