Corneal Ectasia

What is corneal ectasia?

Corneal ectasia refers to a group of conditions that affect your cornea, or the clear, outermost layer of your eye. Corneal ectasia gradually changes the shape of your cornea. Your cornea thins and bulges outward, leading to astigmatism that continues to get worse. As a result, the sharpness of your vision reduces over time. Corneal ectasia usually affects both eyes, but occasionally, affects just one.

Corneal ectasia ranges from mild to severe. It can be so mild that it doesn’t even show up on clinical tests. But as it progresses, your vision may become so impaired that glasses or contacts no longer help. The condition rarely leads to serious complications like blindness. However, impaired vision can place a burden on your daily life and make it hard to work or take care of your family.

Early diagnosis and treatment are essential to manage your condition.

What are the types of corneal ectasia?

There are several types of corneal ectasia, including:

• Keratoconus: This type is most common. Your cornea thins and gradually bulges outward. This makes your eye cone-shaped rather than round.
• Keratoglobus: This is extreme thinning and corresponding bulging throughout your cornea.
• Pellucid marginal degeneration: There’s a crescent-shaped area of thinning in the lower half of your cornea, with a bulging area above it.
• Post-keratorefractive surgery ectasia: In this case, surgery to correct myopia or other vision problems leads to corneal ectasia. Post-LASIK ectasia is an example. Post-LASIK ectasia affects up to 1 in 166 people who have LASIK eye surgery. However, ectasia can also occur after PRK and other vision correction surgeries on your cornea.
• Post-penetrating keratoplasty ectasia: In this case, ectasia occurs as a complication of a cornea transplant. Most often, this affects people who have a cornea transplant to treat keratoconus (occurring in as many as 1 in 10 people within 10 years of surgery).

Who does corneal ectasia affect?

Corneal ectasia affects people of all ages and ethnicities. All sexes and genders are equally affected. Corneal ectasia can begin in childhood and progress into middle age and beyond. The typical age of onset (when the condition begins to show symptoms) varies based on the condition:

• Keratoglobus: Childhood or teens.
• Keratoconus: Teens or 20s.
• Pellucid marginal degeneration: 20s, 30s or 40s.
• Post-surgery ectasia: Anywhere from months to years after your surgery.

What are the symptoms of corneal ectasia?

Corneal ectasia may have no symptoms, especially in the early stages. Possible symptoms include:

• Vision that gets worse over time.
• Glare.
• Halos around lights.
• Double vision (diplopia).

The most common of these symptoms is vision that keeps getting worse over the years. The impact may be mild at first, and glasses may easily correct your vision. But as time goes on, your vision may get worse to the point where glasses or even contacts don’t help enough.

This is because corneal ectasia changes the shape of your cornea and causes astigmatism to get more severe. Some forms (like keratoconus) can also cause scarring of your cornea, which reduces your vision.

Complications of corneal ectasia

Rarely, corneal ectasia can lead to serious complications like corneal hydrops. This is sudden swelling of your cornea. This medical emergency affects up to 3% of people with keratoconus. Symptoms of corneal hydrops include:

• Sudden blurred vision.
• Sensitivity to light.
• Intense pain.

If you have these symptoms, call 911 or your local emergency number immediately.

What causes corneal ectasia?

Often, the exact cause is unknown. Keratoconus and keratoglobus seem to run in biological families. Ectasia that occurs following surgery happens due to underlying weakness in your cornea that didn’t show up in testing prior to surgery.

What are the risk factors?

You may face a higher risk for corneal ectasia if you:

• Have a connective tissue disease, such as Ehlers-Danlos syndrome.
• Have a condition that leads to eye rubbing, such as hay fever or eczema.
• Wear contact lenses, especially hard lenses.
• Undergo vision correction surgery.

How is corneal ectasia diagnosed?

Eye care specialists diagnose corneal ectasia through:

• A comprehensive eye exam.
• Talking with you about your medical history and family history.
• Testing, including a slit lamp exam and corneal topography.

Early diagnosis can help your provider plan the best possible treatment plan. This is why it’s important to visit a provider each year for an eye exam, especially if you have a history of keratoconus or other eye conditions.

Diagnosis is also essential before vision correction surgery, such as LASIK or other surgeries on your cornea. Corneal surgery can make existing ectasia worse, even if it’s mild or causes you no symptoms at the time of your surgery. Therefore, your provider will run tests before your surgery to make sure you’re low-risk.

Can corneal ectasia be fixed?

Different treatment options are available for corneal ectasia, ranging from glasses to surgery. Ophthalmologists tailor treatment to your individual needs. Which treatments you need will depend on the severity of your condition and how well you can see.

Treatment options include:

• Glasses.
• Contact lenses.
• Surgery.

Glasses

Glasses help you see better but don’t affect the progression of the disease. Glasses are a first-line treatment that mostly help in the earliest stage of corneal ectasia.

Contact lenses

Like glasses, contacts help you see better but can’t stop or slow disease progression. They aid in the early or moderate stages. There are many different types of contacts (including soft and hard). Your provider will select the best option for you.

Surgery

Surgery is typically most appropriate in moderate or advanced stages of corneal ectasia. Your ophthalmologist will first try conservative measures (glasses and contacts) as long as your vision is good enough to function daily. But once glasses and contacts can’t correct your vision enough, or if imaging tests show disease progression, you may need surgery. Surgery is different from glasses and contacts, in that it can actually slow or stop disease progression.

If your provider recommends surgery, you might wonder which kind you need or what comes next. It’s important to take the time to learn about the surgical options. Each surgery comes with its own benefits and risks. Talk to your provider to learn more about these surgeries and which might be appropriate for you. Surgical options include:

• Corneal ring implantation: This surgery implants small devices into your cornea to smooth out its shape. This improves your cornea’s ability to bend light as it hits your eye, in turn, sharpening your vision. Corneal rings are also called intrastromal corneal ring segments (ICRS).
• Corneal cross-linking (CXL): This surgery strengthens your cornea by improving the bonds between its collagen fibers. Collagen fibers give your cornea its shape. CXL can slow down or stop the progression of corneal ectasia. It’s especially helpful when performed before the disease has progressed too far.
• Cornea transplant: This surgery gives you a new cornea (from a human donor). Surgeons use different options depending on how much of your corneal tissue is damaged. For example, with deep lamellar keratoplasty (DALK), a surgeon removes only the top and middle layers of your cornea and keeps the lowermost layer in place. This is different from penetrating keratoplasty, which replaces all the layers of your cornea.

How can I reduce my risk?

Unfortunately, you can’t prevent most forms of corneal ectasia. But catching it early can help you receive treatment at the right time and avoid factors that would speed up the progression. You can improve your chances of an early diagnosis by:

• Getting yearly eye exams.
• Asking your provider about your risk of corneal ectasia before having vision correction surgery.
• Learning if any of your biological family members have a history of corneal ectasia (and sharing this information with your provider).

What is the outlook for this condition?

Your healthcare provider is the best person to ask about your outlook. They know the condition of your eyes and your medical history. They can tell you what to expect going forward based on your history and test results. If you have questions or concerns, don’t hesitate to reach out to get the answers you need.

How do I take care of myself?

Most lifestyle changes don’t affect corneal ectasia. But rubbing your eyes can make some types of corneal ectasia worse. Try to avoid rubbing your eyes as much as possible. If this is difficult for you for any reason, talk to an ophthalmologist or a primary care doctor. They can offer advice and, when appropriate, medications. For example, medications for some allergies may help reduce the urge to rub your eyes.

When should I see my provider?

Your provider will tell you how often you should come in for follow-ups. It will depend on which type of corneal ectasia you have, its severity and which treatments you’re receiving.

You may need follow-ups as often as every three to six months to check for disease progression. Such frequent follow-ups allow your provider to determine the best timing for treatments.

It’s essential to go to all of your appointments. Your provider will closely monitor your condition and perform testing as needed to plan treatment. Corneal ectasia requires diligent care to preserve your vision as much as possible.

If you have symptoms of corneal ectasia, including vision that seems to be getting worse, call your provider and schedule an appointment. You should do this even if it’s not yet time for your yearly eye exam.

When should I go to the ER?

Call 911 or your local emergency number if you have:

• Sudden or severe eye pain.
• Sudden blurred vision or double vision.
• Swelling (edema) in your eye.

These can be signs of a medical emergency that needs care right away.

What is the difference between corneal ectasia and keratoconus?

It can be easy to confuse these terms. Corneal ectasia is the umbrella category. Keratoconus is the most common type of corneal ectasia. Research shows anywhere from 1 in 400 to 1 in 2,000 people have keratoconus. However, research also suggests these numbers might underestimate the actual number of people with the condition.

A note from Cleveland Clinic

Corneal ectasia can cause stress, worry and frustration as you try to work, raise a family or simply go about your daily life. Thankfully, treatment options continue to improve. Some surgeries give you the chance to slow or stop the progression of the disease. Talk to an eye care specialist about the best path forward for you.