Corneal dystrophies are eye diseases that involve changes in the cornea (the clear front layer of your eye). These diseases usually run in families.

Most corneal dystrophies are progressive — they get worse over time. Some cause vision loss or pain, but some have no symptoms. The only way to know for sure if you have a corneal dystrophy is to get a comprehensive dilated eye exam. Your eye doctor will use a microscope with a bright light attached (called a slit lamp) to check your eyes for signs of corneal dystrophies.

Lattice dystrophy usually begins in childhood. It causes material to build up on the cornea in a lattice (grid) pattern. As the material builds up, it can cause vision problems.

Map-dot-fingerprint dystrophy (also called epithelial basement membrane dystrophy) is most common in adults ages 40 to 70. It causes a layer of the cornea to develop folds that can look like continents on a map, clusters of dots, or small fingerprints. Sometimes these folds cause vision problems, which may come and go over time.

Lattice dystrophy and map-dot-fingerprint dystrophy can both cause corneal erosion, when the outer layer of the cornea isn’t attached to the eye correctly and starts to erode (wear away).

Symptoms of corneal erosion include:

• Eye pain that’s worse in the morning and gets better later in the day
• Feeling like there’s something in your eye
• Blurry vision
• Sensitivity to light
• Watery eyes

Treatments include eye drops, ointments, and special eye patches or contact lenses that stop your eyelid from rubbing against your cornea. If you have severe corneal erosions or corneal scarring, you may need a surgical treatment, like laser eye surgery or a corneal transplant.

Keratoconus is usually diagnosed in teens and young adults. It causes the middle and lower parts of the cornea to get thinner over time. While a normal cornea has a rounded shape, a cornea with keratoconus can bulge outward and become a cone shape. This different cornea shape can cause vision problems.

Symptoms of keratoconus include:

• Itchy eyes
• Double vision
• Blurry vision
• Nearsightedness (when far-away objects look blurry)
• Astigmatism (when things look blurry or distorted)
• Sensitivity to light

As keratoconus gets worse, it may cause eye pain and more serious vision problems.

Most people with keratoconus can correct their vision problems by wearing glasses, soft contact lenses, or special hard contact lenses that change the shape of the cornea. Your doctor may also recommend a procedure called corneal cross-linking to strengthen your cornea. If your keratoconus causes severe corneal scarring or you have trouble wearing contact lenses, you may need a corneal transplant.

Most people with Fuchs’ dystrophy start to have symptoms around age 50 to 60. This disease makes a type of cornea cells (called endothelial cells) stop working. When these cells stop working, the cornea swells and gets thicker. These cornea changes can cause vision problems.

Symptoms of Fuchs’ dystrophy include:

• Blurry vision that’s worse in the morning and gets better later in the day
• Glare and halos in your vision that make it hard to see things at night or in low light
• Cloudy corneas
• Sensitivity to light

As Fuchs’ dystrophy gets worse, it may cause eye pain and more serious vision problems.

Treatments for Fuchs’ dystrophy include eye drops, ointments, and special contact lenses to help reduce corneal swelling. If your disease is more severe, you may need a corneal transplant.

NEI-supported researchers are always working to better understand, diagnose, and treat conditions that affect the cornea (the clear front layer of the eye). Learn about some recent developments in corneal research.

Corneal wound healing

NEI supports research to understand how the cornea naturally heals after injury, including how certain proteins help to close a layer of the cornea (called the epithelial layer) over the wound. This research could help find new treatments to fix damaged corneas.

Corneal transplants

While most corneal transplants are successful, organ rejection can cause some corneal transplants to fail. NEI supports research into the causes of rejection and new ways to prevent it. One goal is to find alternatives to the immunosuppressive medicines people have to take after transplant surgery, because these medicines can increase the risk of infection.

Artificial corneas

The need for corneal transplants is greater than the supply of donor corneas. NEI supports research to develop new types of artificial corneas to fill this need, including:

• An artificial cornea that combines live corneal cells with other materials
• A folding artificial cornea that doctors can inject into the eye through a very small opening

Corneal dystrophies

NEI supports research to improve early diagnosis and treatment of corneal dystrophies, like keratoconus and Fuchs’ dystrophy. Some recent research aims to:

• Diagnose keratoconus using a high-resolution ultrasound to measure the thickness of corneal layers
• Understand how genetic risk factors for keratoconus affect corneal cells, which could help find new treatments
• Treat keratoconus with corneal collagen cross-linking, a minimally invasive surgery that strengthens the cornea using UV light
• Find the genetic mutations associated with Fuchs’ dystrophy, which could help find new gene therapy treatments

Ocular herpes

Herpetic stromal keratitis caused by ocular herpes is the most common cause of corneal blindness in the developed world. One group of researchers is developing a vaccine to prevent herpes from infecting the cornea.

Stem cell research

NEI supports research to develop endothelial stem cell lines. This research aims to:

• Create stem cell lines that researchers can use to test new treatments in the lab
• Implant stem cells in the eye to grow new, healthy corneal tissue after the cornea is damaged