Corneal dystrophies are a group of rare, genetic diseases that affect the cornea, the front part of your eye. There are more than 20 types, each with different symptoms. All cause a buildup of foreign material in one or more layers of your cornea. Over time, your vision may become cloudy or blurry.
Corneal dystrophies also:
- Tend to run in families
- Often affect both eyes, although one could be worse than the other
- Affect men and women equally, except for Fuchs’ dystrophy, which affects mostly women
- Don’t affect other body parts
- May happen even if you’re in good health
Keep in mind that corneal dystrophies get worse slowly. It often takes years, even decades, before you’ll notice problems. Some people with corneal dystrophies have no symptoms.
What Are the Types of Dystrophies?
Corneal dystrophies are grouped by which layers of the cornea they affect. There are three major categories (some doctors use four).
- Anterior or Superficial Corneal Dystrophies
These dystrophies affect the outer two layers of your cornea: the epithelium and the Bowman’s membrane. They include:
- Epithelial basement membrane dystrophy
- Lisch corneal dystrophy
- Meesmann corneal dystrophy
- Reis-Bucklers corneal dystrophy
- Thiel-Behnke corneal dystrophy
Many of these types begin before the age of 20 but may take years before they cloud your eyesight.
The most common type of this group is epithelial basement membrane dystrophy, also known as map-dot-fingerprint dystrophy. That’s because during an eye exam, your doctor may see dots, fingerprint shapes, or gray areas similar to a map on your cornea. Many people with this disease are symptom-free.
- Stromal Corneal Dystrophies
These dystrophies usually affect the stroma, or center layer of your cornea. They may also progress into other layers. Types in this group include:
- Gelatinous drop-like corneal dystrophy
- Granular corneal dystrophy
- Lattice corneal dystrophy
- Macular corneal dystrophy
- Schnyder crystalline corneal dystrophy
These dystrophies often start when you’re a child or teenager. Some may hurt your vision within a few years. With others, it may take decades before you’ll notice problems.
The most common of these are the lattice dystrophies. They get their name from the lattice pattern that’s formed when abnormal deposits of protein grow over your stroma. Lattice most often appears between ages 2 and 7, but it may start at any age.
- Posterior Corneal Dystrophies
This group affects the two innermost layers: the Descemet membrane and the endothelium. Included in this group are:
- Congenital hereditary endothelial dystrophy
- Fuchs’ endothelial corneal dystrophy
- Posterior polymorphous corneal dystrophy
Many of the dystrophies in this group appear early in life, sometimes at birth.
The most common is Fuchs’ corneal dystrophy, which usually starts when you’re in your 40s or 50s. It may take several more years, even decades before you notice vision problems. With Fuchs’, the cells that pump excess moisture out of your cornea to keep it clear start to die. Over time, moisture builds up and clouds your vision.
What Are the Symptoms of Corneal Dystrophies?
Besides cloudy or blurry vision, here are some of the other ways corneal dystrophy might affect you.
- Watery eyes
- Dry eyes
- Sensitivity to light
- Pain in the eye
- The feel of something in your eye
- Corneal erosions
How severe your symptoms are varies by the type of dystrophy you have.
This is when the epithelium, or front layer, doesn’t stay attached to the rest of your cornea. The most common symptom is pain that may range from mild to severe. In the morning, you may notice your eyelid sticks to your eye.
How Are Corneal Dystrophies Diagnosed?
Most of the time your doctor will find a corneal dystrophy during a routine exam. A special tool called a slit lamp microscope let them see abnormal deposits on your cornea before you notice problems. If you have a family history of corneal dystrophy, be sure to mention it to your doctor.
What Are My Treatment Choices?
Treatment depends on your symptoms and type of dystrophy. If you don’t have symptoms, the doctor may suggest regular checkups to keep track of the disease. As your symptoms get worse, other treatment options include eye drops and ointments.
If your vision is bad enough, the doctor may suggest a corneal transplant. They’ll remove all or just a few layers of your cornea and replace it with healthy tissue from a donor. These are the most common type of transplants in the world and are highly successful.
The doctor may want to replace all or part of your cornea, depending on what type of dystrophy you have. Partial transplants usually heal faster. Talk to your doctor about what kind of surgery is best for you.