Corneal Cross-Linking

Keratoconus: an irregular, protruding
cornea.  Photo via clspectrum.com

In my last post about keratoconus, I mentioned a promising new treatment called corneal cross-linking.       This procedure is still undergoing FDA approval, but more and more ophthalmologists across the states are starting to offer this treatment. Because this procedure is so new in the States, there is still much to learn.  Here is a breakdown of the information I have about corneal cross-linking:

What is corneal cross-linking?

The cornea is made up a collagen fibers that are woven together to make a tight and strong (and clear!) tissue.  In keratoconus, these collagen fibers are somehow weakened, causing the cornea to become misshapen, irregular, and scar over.  This results in devastating vision loss.  Corneal cross-linking is a process where the collagen fiber connections are strengthened again, so that the cornea can maintain its shape and clarity.   Cross-linking actually happens naturally as we age (the collagen fibers tend to strengthen their attachments around age 40) which is why keratoconus tends to be a degeneration of the young eye, and stabilizes later in life.

The Treatment Procedure

I won't begin to go into exact details (this blog is for everyone, not technical scientists!), but the general process is easy to explain.  Your ophthalmologist will apply riboflavin to the eye (after they prepare your cornea to improve penetration of the liquid riboflavin into the deeper layers of the eye).  Then your eye is exposed to UV light for around 30 minutes, which causes the chemical "strengthening" reaction between collagen fibers.  Studies have shown that this procedure increases the corneal "rigidity" by 328%!  You will be conscious the entire time of the procedure and should experience no pain.

Cross-linking procedure.  Riboflavin has been applied, and now UV light
is being shone on the eye. Photo via clspectrum.com

Benefits
Of all studies so far completed (about 691 eyes worldwide have been done), an impressive 92% of patients saw NO progression of their keratoconus 1 year after the procedure.  55% (up to 81% in some studies!) of people saw their vision improve by 1 line or more.  In summary: with this procedure, your eyes should stabilize, and may even improve a little.

Vision is usually worse right after the procedure, and for as long as 6 weeks afterward.  Improvement in vision will begin to be evident by 3-6 months after the surgery date.

Potential Risks
In rare cases (8% from the recent research), the cornea can develop a permanent haze.  To avoid this risk, the cornea needs to be over 400 microns thick (this is a measurement that the surgeon will take prior to performing the procedure).

Who is a candidate?
Corneal cross-linking is ideal for patients with keratoconus who are under 35.  It can also be considered in older patients if their keratoconus is progressing.  You will still need glasses or contact lenses after the procedure, and your prescription may change afterwards.

Cost?
Because it is not yet FDA approved, the procedure is not covered by medical insurance.  Costs across the nation are $3-6,000.

In North Carolina, Dr. Patrick Laber is now offering the procedure.  (Most information provided in this post is courtesy of his detailed explanations!)