What Is Corneal Cross-Linking For Keratoconus?
In CXL, a solution of riboflavin (a type of vitamin B) is applied to the cornea and then the front surface of the eye is exposed to a controlled amount of ultraviolet (UV) light. The UV activates a process whereby the riboflavin creates additional bonds between connective tissue fibers made of collagen within the cornea. These "cross-linkings" provide additional strength and rigidity to the cornea.
There are two types of corneal cross-linking, depending on whether the outer layer of the cornea (the epithelium) is left intact or removed prior to the application of riboflavin solution. In "epi-on" CXL, the epithelium is left intact; in "epi-off" CXL the epithelium is removed.
Corneal cross-linking also is used to stabilize the cornea in cases of a rare complication of LASIK surgery called corneal ectasia, which produces similar signs and symptoms as those of keratoconus.
Page updated January 2021