Keratoconus is an eye condition that affects one in every two thousand Americans. It involves progressive thinning and weakening of the central cornea, causing it to bulge and develop a cone shape, thus losing its normal dome shape. This is called irregular astigmatism.
The abnormal curvature of the cornea causing your vision to become increasingly distorted. As the condition worsens and the front of the cornea expands, you begin to only see up close objects clearly (nearsightedness). Anything too far away appears blurry.
Keratoconus is more prevalent in teenagers and adults in their 20’s. It can progress gradually or quickly and usually affects both eyes. Unfortunately, untreated progressive keratoconus can cause corneal swelling and severe scarring which may impair vision.
Signs and symptoms of keratoconus can include:
The cause of keratoconus is not fully understood. There is a known genetic connection since ten percent of keratoconus sufferers have a parent with the condition. It’s also often seen more often in patients who suffer from retinitis pigmentosa, Down syndrome, Ehlers-Danlos syndrome, hay fever, and asthma.
Some medical researchers theorize that an enzyme imbalance within the cornea makes it vulnerable to damage from free radicals which causes the cornea tissue to weaken and bulge.
It’s thought that frequent vigorous eye rubbing can increase your risk of developing keratoconus. Additionally, overexposure to ultraviolet rays, improper contact lens wear, and chronic eye irritations may also increase your odds of developing keratoconus.
Typically, keratoconus is diagnosed during an eye exam when an ophthalmologist observes the irregularly shaped cornea. Symptoms such as sudden vision change, newly blurred vision in one eye, distorted vision of objects near and far, seeing halos or streaking lights, or difficulty with night driving are all associated with keratoconus.
As part of a comprehensive eye exam, your doctor measures the shape of your cornea to screen for keratoconus. By taking annual measurements, we can detect and track subtle changes that are seen in the early stages of keratoconus.
At AGEI, we use state of the art corneal topography which involves taking a photo of the cornea to analyze its surface shape and characteristics in just a few seconds.
Early diagnosis of keratoconus is very important because we can usually correct the vision errors caused by keratoconus with glasses or special contact lenses that gently molds your cornea in order to correct your vision while you’re wearing the lens.
Early treatment options, which can often provide an excellent quality vision for many years, include:
Rigid gas permeable lenses are made of a specialized plastic that transmits oxygen, these lenses temporarily reshape your cornea’s curvature while you are wearing them in order to correct your vision.
While these are usually more comfortable than rigid gas permeable lenses, their vision correction may not be as crisp.
These are over-sized contact lenses whose outer rim extends to the white of your eye, known as the sclera. These lenses vault over the cone-shaped part of your cornea without touching its surface due to a special fluid-filled reservoir that lies over the cone-shaped cornea, thus restoring clear vision comfortably.
Finding proper fitting corrective lenses is crucial because poorly fitting lenses can result in corneal scarring which will result in you being unable to tolerate any lens. Of course, the best type of corrective contacts can be different for each person. At AGEI we have contact lens fitting experts who can help identify the lens option that will provide you with the best quality of vision and comfort.
If caught early, the progression of keratoconus can be arrested with a treatment called Collagen Crosslinking. This is the only FDA approved technology for slowing or stopping the progression of keratoconus. Because collagen cross-linking is most effective during the early stage of keratoconus, early detection is key.
Cross-Linking Collagen involves activating riboflavin (vitamin B) using ultraviolet light to generate collagen bonds between corneal fibers. In fact, this treatment can strengthen your cornea by up to 300%. By strengthening your cornea in this way, the bulging process is slowed down.
Studies have found that combining keratoconus contact lens wear with corneal cross-linking appears to be even more effective in avoiding transplantation surgery than either treatment alone.
Intacs is a keratoconus treatment introduced over 20 years ago that involves placing concentric plastic rings under the corneal surface to flatten it and improve vision. In fact, AGEI was one of the principal investigators during the initial FDA trials for Intacs.
When the product came on the market, we found Intacs to provide insufficient benefit to our keratoconus patients and so, stopped offering this treatment. We have since noted that Intacs have been associated over the years with a high incidence of complications and thus, we advise against their use at all.
In up to twenty percent of keratoconus patients, the cornea eventually becomes so scarred they can no longer tolerate wearing contact lenses. At this point, a corneal transplant may be the only way to restore vision.
Corneal Transplantation (or Penetrating Keratoplasty) is an out-patient surgery that offers Keratoconus patients excellent results.
The procedure involves removing the abnormal corneal tissue from the eye and replacing it with a graft of healthy corneal tissue from a cadaver donor. The donor cornea graft is held in place with stitches that are one third the width of a human hair.
Our patients usually get excellent results with a cornea transplant, although their vision may stay blurry for months following surgery. You will need to take medicine and use eye drops to avoid graft rejection following a transplant. It is also likely that you will continue to need glasses or contact lenses to achieve your best vision.
Learn more about Cornea Transplants
No! With early detection and treatments like corneal cross-linking and therapeutic contact lenses, a transplant is not a forgone conclusion by any means. These early treatments have proven to be very effective in slowing or stopping the progression of keratoconus.
Dr. Kerry Assil's team are experts in corneal disease management. Dr. Assil's leadership in the field of corneal transplantation surgery began while he was serving on the university faculty in St. Louis decades ago in one of the largest corneal transplant practices in the United States.
Dr. Assil's and his team have performed thousands of corneal transplants and are nationally recognized leaders in the field.
Kerry K. Assil, MD, is regarded as one of the world’s foremost experts in refractive surgery, having made significant advances in the field with his numerous inventions. Additionally he has the unique distinction of having trained thousands of eye surgeons in the latest refractive surgical techniques.
Dr. Assil has authored more than one hundred textbooks, textbook chapters and articles on refractive surgery and has appeared regularly on major television network news programs as a pioneer in refractive surgery. He also leads educational forums for other eye care professionals, which have included featured lectureships at Harvard University, Johns Hopkins University and Tokyo University.