Keratoconus Management and Treatment


Untreated keratoconus can lead to permanent vision loss. The changes to the cornea make it difficult for the eye to focus with or without eyeglasses or standard soft contact lenses.

Keratoconus can be dangerous if laser vision correction surgery such as LASIK is performed on the eye, because it can make the condition worse. Anyone who has even a small degree of keratoconus should not have laser vision correction surgery, unless recommended by the doctor in very specific circumstances.

How is keratoconus treated?

There are several methods for treating keratoconus, depending on how severe the condition is. In the early stages of the disease, vision can be corrected with normal eyeglasses or soft contact lenses.

As keratoconus gets worse, vision may no longer be correctable with eyeglasses because of the amount of irregular astigmatism, and so the patient may need to be fit with a special type of hard contact lens.

For some patients, the disease may advance to a stage at which they do not have acceptable vision even with glasses or contact lenses. At this point, the doctor may recommend a cornea transplant, which is a surgical procedure to replace the cornea with a cornea from a donor.

Two additional treatments for keratoconus are implantable ring segments (often referred to as INTACS) and corneal crosslinking:

  • Implantable ring segments are small devices that are inserted into the cornea to improve vision or make it easier to fit a patient with contact lenses. In this procedure, which is performed under local anesthesia (the patient’s eye is numbed with drops), the doctor creates channels in the cornea and inserts the rings into these channels. The rings help to flatten the cornea and partially correct the cone shape caused by the keratoconus.
  • Corneal crosslinking uses ultraviolet light treatment that may slow or stop the keratoconus from getting worse. In this procedure, the patient also receives local anesthesia. Drops of a drug containing riboflavin (vitamin B2) are put into the eye for up to 30 minutes. The eye is then exposed to an ultraviolet light for up to 30 minutes. The corneal crosslinking procedure is designed to strengthen the bonds between the cornea’s collagen fibers and surrounding proteins, which can help keep the cornea from steepening.

Not all patients with keratoconus are candidates for these treatments. Your doctor can help to decide which, if any, of these treatments may help you.

Does a patient with keratoconus need surgery?

Many patients with keratoconus will never need a cornea transplant. Corneal crosslinking is a major advance in slowing or stopping keratoconus, and treatment is important to consider especially in young patients with evidence of keratoconus so that loss of vision can be minimized.

In cases in which vision can no longer be corrected with glasses or contact lenses, surgery may be recommended.

Keratoconus patients usually experience improved vision with cornea transplantation surgery, although it may take more than a year for vision to stabilize and for a patient to benefit from new glasses or contact lenses.

Some patients still require a specialty contact lens after their corneal transplant to get their best vision.

Last reviewed by a Cleveland Clinic medical professional on 08/19/2019.


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Linkedin Pinterest Eyes What You Need to Know

  • Keratoconus is an eye disease that affects the structure of the cornea, resulting in loss of vision.
  • Keratoconus occurs in approximately one in 2,000 individuals, typically beginning in puberty and progressing into the mid-30s.
  • Early stages can be treated with glasses, but with progression of the disease into late childhood and early adulthood, corneal transplantation may be needed to restore sight.
  • Corneal collagen cross-linking is a procedure designed to stop the progression of keratoconus or slow it down.
  • Keratoconus is a leading cause of corneal transplantation in the United States.
  • There is no known prevention for keratoconus.

Keratoconus is characterized by the thinning of the cornea and irregularities of the cornea’s surface. The cornea is the clear, outer layer at the front of your eye.

The middle layer is the thickest part of the cornea, mostly made up of water and a protein called collagen. Collagen makes the cornea strong and flexible, and helps keep its regular, round shape. This healthy cornea focuses light so you can see clearly.

With keratoconus, the cornea thins and bulges into an irregular cone shape, resulting in vision loss.

Keratoconus generally begins at puberty and progresses into the mid-30s. There is no way to predict how quickly the disease will progress, or if it will progress at all. Keratoconus typically affects both eyes, with one being more severely affected than the other.

What causes keratoconus?

Although keratoconus has been studied for decades, it remains poorly understood.

The definitive cause of keratoconus is unknown, though it is believed that the predisposition to develop the disease is present at birth. A common finding in keratoconus is the loss of collagen in the cornea.

This may be caused by some imbalance between production and destruction of the corneal tissue by the corneal cells.

What are the risk factors for keratoconus?

The following may increase the risk of developing keratoconus:

  • Genetics. Patients with a family history of keratoconus or with certain systemic disorders, such as Down syndrome, are at a higher risk of developing keratoconus.
  • Chronic eye inflammation. Constant inflammation from allergies or irritants can contribute to the destruction of corneal tissue that may result in developing keratoconus.
  • Eye rubbing. Chronic eye rubbing is associated with developing keratoconus. It may also be a risk factor for disease progression.
  • Age. Keratoconus is often discovered in the teenage years. Generally, young patients with advanced keratoconus are more ly to need some form of surgical intervention as the disease progresses.

What are the symptoms of keratoconus?

Many keratoconus patients are unaware they have the disease. The earliest symptom is a slight blurring of vision or progressively poor vision that is not easily corrected.

Other symptoms of keratoconus include:

  • Glare and halos around lights
  • Difficulty seeing at night
  • Eye irritation or headaches associated with eye pain
  • Increased sensitivity to bright light
  • Sudden worsening or clouding of vision

How is keratoconus diagnosed?

In addition to a complete medical history and eye exam, your eye care professional may perform the following tests to diagnose keratoconus:

  • Corneal topography. This is the most accurate way to diagnose early keratoconus and follow its progression. A computerized image is taken that creates a map of the curve of the cornea.
  • Slit-lamp exam. This examination of the cornea can help detect abnormalities in the outer and middle layers of the cornea.
  • Pachymetry. This test is used to measure the thinnest areas of the cornea.

Early Stages

Current treatment for keratoconus includes glasses in the earliest stages to treat nearsightedness and astigmatism. As keratoconus progresses and worsens, glasses are no longer capable of providing clear vision, and patients need to wear a contact lens, usually a hard contact lens.

Intermediate Stages

Progressive keratoconus can be treated by corneal collagen cross-linking. This one-time, in-office procedure involves the application of a vitamin B solution to the eye, which is then activated by ultraviolet light for about 30 minutes or less. The solution causes new collagen bonds to form, recovering and preserving some of the cornea’s strength and shape.

While the treatment cannot make the cornea entirely normal again, it can keep vision from getting worse and, in some cases, may improve vision. The procedure may require the removal of the thin outer layer of the cornea (epithelium) to allow the riboflavin to more easily penetrate the corneal tissue.

Cross-linking was approved as a treatment for keratoconus by the FDA in April 2016, after clinical trials showed that it stopped or produced a mild reversal in bulging of the cornea within three to 12 months after the procedure.

Advanced Stages

  • Corneal ring. With severe keratoconus, a standard contact lens may become too uncomfortable to wear. Intacs are implantable, plastic, C-shaped rings that are used to flatten the surface of the cornea, allowing improved vision. They may also allow a better contact lens fit. The procedure takes about 15 minutes.
  • Corneal transplant. In a corneal transplant, a donor cornea replaces the patient’s damaged cornea. Corneal transplants are often performed on an outpatient basis and take about an hour to complete. Vision usually remain blurry for about three to six months after the transplant, and medication must be taken to avoid transplant rejection. In almost all cases, glasses or a contact lens are necessary to provide the clearest vision after transplant surgery.

Can keratoconus be prevented?

There is no known prevention for keratoconus.


10 Keratoconus Treatments + Causes and Symptoms



Reviewed by William Trattler, MD

Keratoconus is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone- shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina, causing distorted vision.

Keratoconus can occur in one or both eyes and often begins during a person's teens or early 20s.

Keratoconus signs and symptoms

As the cornea becomes more irregular in shape, it causes progressive nearsightedness and irregular astigmatism to develop, creating additional problems with distorted and blurred vision. Glare and light sensitivity also may occur.

Often, keratoconic patients experience changes in their eyeglass prescription every time they visit their eye doctor.

Keratoconus treatment

In the mildest form of keratoconus, eyeglasses or may help. But as the disease progresses and the cornea thins and becomes increasingly more irregular in shape, glasses and regular soft contact lens designs no longer provide adequate vision correction.

Treatments for progressive keratoconus include:

1. Corneal crosslinking

This procedure, also called corneal collagen cross-linking or CXL, strengthens corneal tissue to halt bulging of the eye's surface in keratoconus.

The aim of corneal cross-linking is to strengthen the cornea by increasing the number of “anchors” that bond collagen fibers together. (Diagram: Boxer Wachler Vision Institute)

There are two versions of corneal crosslinking: epithelium-off and epithelium-on.

With epithelium-off crosslinking, the outer layer of the cornea (called the ) is removed to allow entry of riboflavin, a type of B vitamin, into the cornea, which then is activated with UV light.

With the epithelium-on method (also called transepithelial crosslinking), the corneal epithelium is left intact during the treatment. Advantages include less risk of infection, less discomfort and one-day visual recovery.

Avedro’s Photrexa/KXL System currently is the only FDA-approved platform and procedure for corneal crosslinking treatment of progressive keratoconus in the United States. However, eye surgeons can lawfully use other riboflavin/UV light crosslinking protocols to perform less invasive, epithelium-on crosslinking treatment for keratoconus — such as the Holcomb C3-R crosslinking procedure.

Corneal crosslinking may reduce significantly the need for corneal transplants among keratoconus patients. It also is being investigated as a way to treat or prevent complications following LASIK or other vision correction surgery.

Using a combination of corneal crosslinking and Intacs implants also has demonstrated promising results for treating keratoconus. Also, progressive mild to moderate keratoconus has been safely and successfully treated with a combination of corneal crosslinking and implantation of a toric phakic IOL.

2. Custom soft contact lenses

Recently, contact lens manufacturers have introduced custom soft contact lenses specially designed to correct mild-to-moderate keratoconus. These lenses are made-to-order detailed measurements of the person's keratoconic eye(s) and may be more comfortable than gas permeable lenses (GPs) or hybrid contact lenses for some wearers.

In the United States, custom soft contacts that are available for the correction of keratoconus include:

  • KeraSoft lenses (Bausch + Lomb). These high-water silicone hydrogel lenses can correct up to 20 (D) of nearsightedness or farsightedness and up to -12 D of astigmatism.
  • NovaKone lenses (Bausch + Lomb). These medium-water hydrogel lenses can correct up to 30 D of nearsightedness or farsightedness and up to -10 D of astigmatism.

Both lenses have a very wide range of fitting parameters for a customized fit and are larger in diameter than regular soft lenses for greater stability on a keratoconic eye.

Custom toric soft contacts for keratoconus are significantly more expensive than regular soft contacts, but vision insurance may cover some of the costs associated with contact lenses for keratoconus.

SEE ALSO:Answers From An Eye Doctor About Keratoconus >

3. Gas permeable contact lenses

Because eyeglasses and soft contact lenses often cannot provide adequate visual acuity in cases of keratoconus, gas permeable contact lenses usually are the preferred treatment. GP lenses vault over the cornea, replacing its irregular shape with a smooth, uniform refracting surface to improve vision.

Fitting contact lenses on an eye with keratoconus often is challenging and time-consuming. You can expect frequent return visits to your eye care provider so he or she can fine-tune the fit and your prescription, especially if your keratoconus continues to progress.

For progressive keratoconus, only Avedro's corneal cross-linking procedure is FDA approved and widely covered by insurance.

In 2016, Avedro's corneal cross-linking procedure became the first and only FDA approved corneal cross-linking treatment for progressive keratoconus. Since then, the procedure has been completed more than 18,000 times at more than 300 practices nationwide.

Today, the treatment is widely covered by commercial insurance. Click here to view your insurance policy

Supported by the National Keratoconus Foundation, this safe, minimally invasive outpatient procedure works by stiffening the weakened cornea to slow or halt progression of the disease.

Make sure your cross-linking is FDA-approved and covered by insurance. Click here to find a cornea specialist near you

Approved uses

Photrexa Viscous® (riboflavin 5’-phosphate in 20% dextran ophthalmic solution) and Photrexa® (riboflavin 5’-phosphate ophthalmic solution) are used with the KXL®System in corneal cross-linking to treat eyes in which the cornea, the clear dome shaped surface that covers the front of the eye, has been weakened from the progression of the disease keratoconus or following refractive surgery, a method for correcting or improving your vision.

Tell your healthcare provider if you are pregnant or plan to become pregnant.

Important Safety Information

Ulcerative keratitis, a potentially serious eye infection, can occur. Your doctor should monitor defects in the outermost corneal layer of the eye for resolution.  

The most common ocular side effect is haze. Other ocular side effects include inflammation,fine white lines, dry eye, disruption of surface cells, eye pain, light sensitivity, reduced sharpness of vision, and blurred vision. The risk information provided here is not comprehensive. To learn more, talk to your healthcare provider.

Go to to obtain the FDA-approved product labeling.

You are encouraged to report all side effects to the FDA. Visit, or call 1-800-FDA-1088.

4. “Piggybacking” contact lenses

Because fitting a gas permeable contact lens over a cone-shaped cornea can sometimes be uncomfortable for a person with keratoconus, some eye care practitioners advocate “piggybacking” two different types of contact lenses on the same eye.

For keratoconus, this method involves placing a soft contact lens, such as one made of silicone hydrogel, over the eye and then fitting a GP lens over the soft lens. This approach increases wearer comfort because the soft lens acts a cushioning pad under the rigid GP lens.

Your eye care practitioner will monitor closely the fitting of “piggyback” contact lenses to make sure enough oxygen reaches the surface of your eye, which can be a problem when two lenses are worn on the same eye. However, most modern contacts — both GP and soft — typically have adequate oxygen permeability for a safe “piggyback” fit.

5. Hybrid contact lenses

The UltraHealth and ClearKone hybrid contact lenses manufactured by SynergEyes combine a highly oxygen-permeable rigid center with a soft peripheral “skirt.” These lenses were designed specifically for keratoconus, and the central GP zone of the lens vaults over the cone-shaped cornea for increased comfort.

Hybrid contact lenses provide the crisp optics of a gas permeable contact lens and wearing comfort that rivals that of soft lenses, according to SynergEyes. UltraHealth and ClearKone are available in a wide variety of parameters to provide a fit that conforms well to the irregular shape of a keratoconic eye.

6. Scleral and semi-scleral lenses

These are large-diameter gas permeable contacts — large enough that the periphery and edge of the lens rest on the “white” of the eye (sclera).

Scleral lenses cover a larger portion of the sclera, whereas semi-scleral lenses cover a smaller area.

Because the center of scleral and semi-scleral lenses vaults over the irregularly shaped cornea, these lenses don't apply pressure to the eye's cone-shaped surface for a more comfortable fit.

These larger lenses also are more stable than conventional gas permeable contact lenses, which move with each blink because they cover only a portion of the cornea.

7. Prosthetic lenses

Eyes with advanced keratoconus may require an advanced prosthetic scleral lens design.

One example are lenses made with the EyePrintPRO process (EyePrint Prosthetics). This system uses proprietary Elevation Specific Technology to exactly match the unique irregularities of each individual eye.

The process begins with an EyePrint Impression, which captures the precise curvatures of the entire ocular surface. Doctors then send the resulting impression to an EyePrint lab for 3-D scanning.

The scanned data is then fed to a numerically controlled machining system to produce a lens that matches the impression exactly and therefore fits the individual cornea and sclera perfectly. Because of the precise nature of the back surface fit, high quality and individualized optics can be placed on the front surface of the device.

“The EyePrint is a fingerprint—it's completely individual,” says EyePrint developer Dr. Christine Sindt, Clinical Associate Professor of Ophthalmology and Visual Sciences at University of Iowa.

The EyePrintPRO can only be fit by doctors who undergo specific training and certification. To learn more and to find an eye doctor who prescribes and fit these prosthetic lenses, visit the EyePrint Prosthetics website .

8. Intacs

Intacs (Addition Technology) are FDA-approved clear, arc-shaped corneal inserts that are surgically positioned within the peripheral cornea to reshape the front surface of the eye for clearer vision.

Intacs may be needed when keratoconus patients no longer can obtain functional vision with contact lenses or eyeglasses.

Several studies show that Intacs can improve the best spectacle-corrected visual acuity (BSCVA) of a keratoconic eye by an average of two lines on a standard eye chart. The implants also have the advantage of being removable and exchangeable. The surgical procedure takes only about 10 minutes.

Intacs might delay but can't prevent a corneal transplant if keratoconus continues to progress.

9. Topography-guided conductive keratoplasty

While more study is needed, early results of a small study involving topography-guided conductive keratoplasty (CK) show this procedure might help smooth irregularities in the corneal surface.

This treatment uses energy from radio waves, applied with a small probe at several points in the periphery of the cornea to reshape the eye's front surface. A topographic “map” created by computer imaging of the eye's surface helps create individualized treatment plans.

10. Corneal transplant

Some people with keratoconus can't tolerate a rigid contact lens, or they reach the point where contact lenses or other therapies no longer provide acceptable vision.

The last remedy to be considered may be a cornea transplant, also called a (PK or PKP). Even after a transplant, you most ly will need glasses or contact lenses for clear vision.

Find an eye doctor near you.

Reviewer – William Trattler

William Trattler, MD, is a board-certified ophthalmologist specializing in refractive, corneal and cataract eye surgery at the Center for Excellence in Eye Care — a private practice in … Read more


Keratoconus – diagnosis and treatment


Keratoconus is a condition where the cornea becomes thin and stretched near its center, causing it to bulge forward into a conical shape. As a result vision becomes distorted.

Keratoconus does not cause total blindness, however, without treatment it can lead to significant vision impairment. With current treatments now available most patients with keratoconus are able to lead normal lifestyles.

Keratoconus is a progressive eye disease, usually affecting both eyes. The degree of progression in each eye is often unequal, and it isn’t unusual for the condition to be significantly more advanced in one eye.

The cornea is the clear surface at the front of the eyeball. It refracts the light entering the eye onto the lens, which then focuses it onto the retina.


The cause of keratoconus is unknown. However, it is believed to be an inherited condition. Some studies have connected keratoconus with allergies such as asthma and eczema. It has also been found that poorly fitted contact lenses and excessive rubbing of the eye may contribute to the cause.


The initial symptom of keratoconus is an irregular shaped cornea, where it appears to ‘bulge’ forward from the eye socket. This may not be that obvious at first, though will develop over time.

Vision is usually affected once the cornea starts to change shape. Blurring, light sensitivity and seeing ghost- images can occur.


Most people with keratoconus begin to develop the condition in their late teens or early 20’s, with the majority of transplants being performed on patients between 20 – 45 years of age.

In Australia keratoconus is estimated to occur in 1 every 2000 people, with no significant prevalence in either males or females.


There are various options for the treatment of keratoconus, including; spectacles/glasses, contact lenses, corneal implants and corneal transplants.

Glasses – In the early stages of keratoconus, glasses are usually successful in correcting the myopia and astigmatism, however as the condition advances the cornea becomes highly irregular and vision is no longer adequately corrected with glasses.

Contact lenses – Contact lenses are used to maintain the regular shape of the cornea, however in 5 – 10% of patients there comes a stage when contact lenses are no longer effective and a corneal transplant is considered.

Contact lenses do not slow down the rate of progression of the conical cornea, however they do give good vision during that period which could not of otherwise be achieved.

Surgery – Corneal transplants have a very high success rate following transplantation, with 98.1% of transplanted corneas surviving the first year, and 97.5% surviving beyond four years. To find out more on corneal transplant procedures, click here.

A thorough examination with your ophthalmologist will help establish which treatment is best for your individual case.

The Lions Eye Institute also conducts an array of Clinical Trials. You can view these on our Clinical Trials page.

Further information and support

For further information on keratoconus, including treatment, recovery, and risks and complications, please consult with one of our ophthalmologists.

What’s Next?

Please contact The Lions Eye Institute to make an appointment with the appropriate ophthalmologist.  A current referral from either a GP, or an optometrist, is required for all appointments.

Australian and international references


Keratoconus: What Does It do to Your Eyes?


  • What Is Keratoconus?
  • Intacs Treatment
  • Corneal Cross-Linking Treatment

We see through the cornea, which is the clear outer lens or “windshield” of the eye.

Normally, the cornea has a dome shape, a ball. Sometimes, however, the structure of the cornea is just not strong enough to hold this round shape and the cornea bulges outward and downward a cone.

This condition is called keratoconus.

Tiny fibers of protein in the eye called collagen help hold the cornea in place and keep it from bulging. When these fibers become weak, they cannot hold the shape and the cornea becomes progressively more cone shaped.

Keratoconus is caused by a decrease in protective antioxidants in the cornea. The cornea cells produce damaging by-products, exhaust from a car. Normally, antioxidants get rid of them and protect the collagen fibers. If antioxidant levels are low, the collagen weakens and the cornea bulges out.

Keratoconus is usually not genetic but sometimes runs in families. If you have it and have children, it’s a good idea to have their eyes checked for it starting at age 10. The condition progresses more rapidly in people with certain medical problems, including certain allergic conditions. It could be related to chronic eye rubbing.

Keratoconus usually starts in the teenage years. It can, though, begin in childhood or in people up to about age 30. It's possible it can occur in people 40 and older, but that is less common.

The changes in the shape of the cornea can happen quickly or may occur over several years. The changes can result in blurred vision, glare and halos at night, and the streaking of lights.

The changes can stop at any time, or they can continue for decades. There is no way to predict how it will progress. In most people who have keratoconus, both eyes are eventually affected, although not always to the same extent. It usually develops in one eye first and then later in the other eye.

With severe keratoconus, the stretched collagen fibers can lead to severe scarring. If the back of the cornea tears, it can swell and take many months for the swelling to go away. This often causes a large corneal scar.

The changes to the cornea can make it impossible for the eye to focus without eyeglasses or contact lenses. In fact, a corneal transplant may be needed to restore vision if the condition is severe.

Laser vision correction surgery — LASIK – is dangerous for people with keratoconus, because it can further weaken the cornea and make vision worse. Anyone with even a small degree of keratoconus should not have LASIK surgery.

Keratoconus changes vision in two ways:

  • As the cornea changes from a ball shape to a cone shape, the smooth surface becomes distorted. This is called irregular astigmatism.
  • As the front of the cornea expands, vision becomes more nearsighted. That is only up close objects can be seen clearly. Anything too far away will look a blur.

An eye doctor may notice symptoms during an eye exam. You may also mention symptoms that could be caused by keratoconus. These include:

  • A sudden change of vision in one eye
  • Double vision when looking with just one eye
  • Objects both near and far looking distorted
  • Bright lights looking they have halos around them
  • Lights streaking
  • Seeing double or triple ghost images
  • Being uncomfortable driving due to blurry vision, especially at night

To be sure you have keratoconus, your doctor needs to measure the shape of the cornea. There are several different ways this can be done.

The most common way is called ‘corneal topography,’ which snaps a photo of the cornea and analyzes it in seconds. Children of parents with keratoconus should have a cornea topography done every year starting at age 10 to monitor the cornea.

Even if your child's corneal topography is normal, it’s still important to have this test performed yearly. There may be subtle changes over time that indicate the disease has started.

With annual tests, your doctor can compare results to identify those changes if they're present.

Treatment usually starts with new eyeglasses. If eyeglasses don't provide adequate vision, then contact lenses, usually rigid gas permeable or scleral contact lenses, may be recommended.

With mild cases, new eyeglasses can usually make vision clear again.

Eventually, though, it will probably be necessary to use contact lenses or seek other treatments to strengthen the cornea and improve vision.

A treatment called cornea collagen crosslinking is often effective to help prevent worsening. Intacs are implants that are placed under the surface of the cornea to reduce the cone shape and improve vision.

A specialized laser procedure called PTK can smooth out a raised scar ( a callus) and improve contact lens comfort.

If eyeglasses and contact lenses no longer provide stable and comfortable good quality vision, a cornea transplant can be performed. This involves removing the center of the cornea and replacing it with a donor cornea that is stitched into place. This is typically only done as a last resort.


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© 2019 WebMD, LLC. All rights reserved. Intacs Treatment


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For more support, visit the Keratoconus Group