Extra, extra! Read all about LAISK Xtra
By now, you’ve probably heard of the laser vision correction technique called LASIK (LASer-assisted In situ Keratomileusis). In fact, you probably know at least one person who has had the procedure performed. While LASIK is generally very safe and very effective at correcting refractive errors, the procedure uses a laser to thin the cornea, weakening it.
How weak does the cornea get?
Most of us have plenty of cornea to spare… more than enough to have LASIK, but some people have corneas that are thinner and having LASIK will thin it out even more. It is estimated that LASIK weakens the cornea by 15 to 25 percent. This could result in decreased corneal rigidity and possible shifting of the corneal shape over time. This shape shifting is called ectasia, and it’s a precursor to keratoconus.
Corneal cross-linking to the rescue
A recently developed technique called corneal cross-linking uses the chemical riboflavin to strengthen the structure of the cornea. A surgeon applies riboflavin to the eye, then activates it with UV light. The riboflavin causes new bonds to form across adjacent collagen strands in the stromal layer of the cornea, which recovers and preserves some of the cornea’s mechanical strength. Corneal cross-linking is currently being applied to cases of corneal ectasia and keratoconus.
Some cornea specialists are now exploring the use of corneal cross-linking in combination with LASIK — dubbed LASIK Xtra — to prevent LASIK from degrading the structural integrity of the cornea. If successful, this technique could reduce the incidence of corneal ectasia and keratoconus after LAISK. It could also reduce rates of regression, or shifting refractive error, after successful LASIK surgery. It is possible that LASIK Xtra (LASIK + corneal cross-linking) should be performed on all LASIK patients. The jury is still out on this and the question will be answered as clinical trials are performed around the world. Stay tuned…