When the cornea thins and becomes irregularly shaped, it is a form of ectasia. In the case of progressive keratoconus, this can cause it to thin out and become cone-shaped.

Ectasia can occur naturally with age, or it can be the result of laser eye surgery, but this is incredibly rare. Corneal cross-linking is a method of treating ectasia, improving the shape of the cornea, and slowing its thinning. Corneal cross-linking can both improve and preserve your vision. (Learn More) It is an extremely successful technology, and the procedure itself has improved and evolved over the past few decades since its inception. (Learn More) Corneal cross-linking is also considered to be very safe and minimally invasive. (Learn More) The procedure generally takes less than an hour or two to perform. Recovery time ranges from a day to a few weeks, depending on the method used. (Learn More)

Success Rates for Corneal Cross-Linking

Overall, success rates for corneal cross-linking are considered to be very high. When the first human trials for the procedure were performed in 2003, all patients suffering from progressive keratoconus saw the progression stop.  In addition, 70 percent of the patients had a decreased keratoconus, and 65 percent experienced visual acuity.

Corneal cross-linking procedures have improved and evolved since 2003. Success rates show an average decrease in keratometry of nearly 75 percent, and visual acuity improvements of more than 70 percent. These findings are stable a full year after the procedure.

Complications for corneal cross-linking are rare, but there can be risks, as with any surgical procedure. Your cornea will need to be thick enough for the procedure to be effective, and there is always a small risk for infection. Your provider will work with you to determine if the procedure is a good fit for you and advise you on how to recover safely if you move forward.

Improvements in Corneal Cross-Linking

Keratoconus is a degenerative disorder that is likely genetic. Your cornea thins with age and can become misshapen, forming a cone-like shape that can cause vision loss and clarity issues. The condition is progressive, meaning that it will continue to thin out and get more irregular with time.

Corneal cross-linking was first developed in Europe in the 1990s, and it was introduced for human trials in 2003. Today, corneal cross-linking uses liquid riboflavin and exposure to UV light to create links between collagen fibers in the cornea to stabilize and strengthen it.

The current procedure was FDA-approved in the United States in 2016. Corneal cross-linking is considered the top choice for controlling the progression of keratoconus.

Additional Uses

Review of Ophthalmology reports that corneal cross-linking can be used off-label to treat some conditions. It can be used to address:

  • Younger patients. The FDA has approved corneal cross-linking for patients 14 and older. Keratoconus is progressive, and it can advance rapidly once it starts. Some surgeons are treating younger patients with positive results.
  • Patients over 40 years old. Typically, the progression of keratoconus stops between ages 25 and 35, but older patients can still benefit from corneal cross-linking too.
  • Corneal infections. Bacterial infections should still first be addressed with antibiotics, but corneal cross-linking can have some positive impact as well.
  • Refractive errors. Corneal cross-linking may be able to positively address refractive errors that are related to irregularly shaped corneas.
  • Complex cases. Cross-linking can be combined with LASIK or PRK. This can help to reshape the topography of the cornea while also addressing keratoconus at the same time.

Corneal Cross-Linking Is Safe & Effective

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Corneal cross-linking is an outpatient and minimally invasive procedure that usually takes between 30 and 90 minutes to complete. Usually, one eye is done at a time.

First, your eye will be bathed in riboflavin in liquid form, which is vitamin B2. It will then be exposed to ultraviolet (UV) light in a controlled fashion.

There are two ways to do this procedure: epithelium-on or epithelium-off. With epithelium-off corneal cross-linking, the thin layer on the outside of your cornea is removed first to let the riboflavin solution penetrate deeper into your cornea. This procedure is more invasive than the epithelium-on version of corneal cross-linking, which leaves this outer layer intact.

FDA-approval for corneal cross-linking in the United States involves the epithelium-off procedure with Avedro's KXL system. The thickness of your cornea is measured first to make sure you are a prime candidate for the procedure.

There are minimal reported complications of this procedure. It is considered to be both a safe and effective treatment for corneal ectasia.

Progression of keratoconus can be stopped and stabilized to ensure that vision doesn't worsen due to the degenerative disorder.

Recovery Timeline & Expectations

If you undergo an epithelium- on corneal cross-linking procedure, you will likely have minimal pain after the surgery, and your cornea can heal in as little as a day. For an epithelium-off corneal cross-linking procedure, you will be prescribed topical anti-inflammatory and antibiotics for your eye. A bandage contact lens will be put on your eye to help it heal faster and to minimize potential discomfort.

It can take a few weeks for your cornea to heal completely from an epithelium-off corneal cross-linking procedure. Follow all instructions from your doctor regarding recovery and how to take care of your eye after surgery.

Recovery usually follows this type of timeline:

  • Three to five days after surgery, your eye may be sensitive to light. You may experience some discomfort.
  • You will need a follow-up appointment three to four days after the procedure. Your doctor will remove the bandage contact lens.
  • One week after the procedure, you can start driving again, and you will usually feel well enough to return to work. You should also have a second follow-up appointment at this time to provide full clearance and confirm that things are healing properly.
  • Three months after surgery, you should have another checkup to see how things look. By this point, your cornea should be completely healed.

You may experience blurry and decrease vision acuity for a few days to a few weeks directly after a corneal cross-linking procedure, but things should improve with healing.

To speed the healing process, protect your eyes from the sun for the first several days. Consider wearing sunglasses when you go outside. Rest properly, and follow all the recovery instructions given to you by your doctor and the providers at the eye center.

The overarching goal of corneal cross-linking is to stop progressive keratoconus from getting worse. The majority of the time it is a successful procedure, and you can fully heal relatively quickly.

References

Analysis of 2-Year Corneal Cross-Linking Results in Keratoconus Patients. (May 2014). Journal of the Egyptian Ophthalmological Association.

Corneal Collagen Cross-Linking. (January 2015). American Academy of Ophthalmology. (AAO).

Your Top 12 Crosslinking Questions- Answered! (January 2018). Review of Optometry.

Making the Most of Corneal Cross-Linking. (November 2018). Review of Ophthalmology.

Corneal Cross-Linking Treatment for Keratoconus. (June 2019). All About Vision.

What Is Corneal Cross-Linking? WebMD.

Making the Most of Corneal Cross-Linking. (November 2018). Review of Ophthalmology.

When to Consider Corneal Cross-Linking Treatment. (May 2019). Ophthalmology Times.