Corneal Dystrophy

Corneal dystrophies are a group of genetic eye disorders where abnormal material gathers in the clear outer layer of the eye known as the cornea. There are over 20 subdivisions of corneal dystrophy. To learn more specific information on the types of corneal dystrophy, click here. Corneal dystrophies can be classified into three major categories:

• Anterior or superficial corneal dystrophies affect the outermost layer (front) of the cornea called the epithelium and Bowman’s layer.
• Stromal corneal dystrophies affect the stroma, which is the middle and thickest layer of the cornea.
• Posterior corneal dystrophies affect the inner part of the cornea called the endothelium and the Descemet’s membrane. The most common type of posterior corneal dystrophy is Fuchs’ dystrophy.

The age, onset and specific symptoms will vary among individuals according to the type of corneal dystrophy. However, most forms of corneal dystrophy have similar characteristics. Corneal dystrophy usually:

• Affects otherwise healthy people
• Is found in males and females alike, except for Fuchs’ dystrophy which affects more women than men
• Affects both eyes
• Progresses very slowly
• Tends to run in families
• Is not caused by outside sources like injury or diet
• Originates in specific layers of the cornea but can spread to nearby layers
• Does not affect other parts of the body
• Is not related to other diseases in other parts of the body

Most forms of corneal dystrophy are inherited as autosomal dominant traits, which mean that only one parent has to contribute the gene for corneal dystrophy for the child to be affected. A few types of corneal dystrophy are autosomal recessive, meaning that both parents must contribute the gene for the disease.

The symptoms of corneal dystrophy depend on the type of disease, and symptoms can vary from completely asymptomatic to vision loss. The build-up of material in the cornea can actually cause the cornea to become opaque, which leads to blurred vision and vision loss.

Some individuals experience corneal erosion, in which the outermost layer of the cornea called the epithelium fails to attach to the next layer. This can cause mild to severe pain, sensitivity to light, blurred vision and the sensation that there is a foreign body in the eye.

If your eye doctor thinks that you may have corneal dystrophy, he or she will inquire about your family history. A slit lamp microscope will allow your eye doctor to examine the front portion of the eye. Even if there are no symptoms, a comprehensive eye examination may detect corneal dystrophy. In other cases, genetic testing may be used to diagnose corneal dystrophy.

Treatment varies widely. Regular care from your eye doctor can monitor the progression of the disease. If symptoms are not present, treatment may not be required.

In other cases, individuals may experience corneal erosion, and this requires treatment. There are many different types of treatment for corneal erosion, but initial therapies include antibiotics, lubricating eye drops, ointments or special soft contact lenses. If corneal erosion continues, advanced treatment includes laser therapy or a procedure that scrapes the cornea.

In the most severe cases, a corneal transplant may be required. This is called a keratoplasty. In this procedure, the diseased corneal tissue is removed and replaced with donor corneal tissue. Certain types of dystrophy like Fuchs’ dystrophy would only require a partial corneal transplant called an endothelial keratoplasty.