Cross-linking is a minimally invasive outpatient procedure that combines the use of UVA light and riboflavin eye drops to add stiffness to corneas which have been weakened by disease or refractive surgery. Cross-linking, which has been performed in Europe since 2003, is considered the standard of care around the world for keratoconus and corneal ectasia following refractive surgery.
What are the benefits of Corneal Cross-Linking?
- Creates new corneal collagen cross-links
- Results in a shortening and thickening of the collagen fibrils
- Leads to the stiffening of the cornea
Riboflavin
Riboflavin (vitamin B2) is important for body growth, red blood cell production and assists in releasing energy from carbohydrates. Its food sources include dairy products, eggs, green leafy vegetables, lean meats, legumes, and nuts. Breads and cereals are often fortified with riboflavin.
Under the conditions used for corneal collagen cross-linking, riboflavin 5’-phosphate, vitamin B2, functions as a photoenhancer which enables the cross-linking reaction to occur.
Ultra-Violet A (UVA)
UVA is one of the three types of invisible light rays given off by the sun (together with ultra-violet B and ultra-violet C) and is the weakest of the three.
A UV light source is applied to irradiate the cornea after it has been soaked in the photoenhancing riboflavin solution. This cross-linking process stiffens the cornea by increasing the number of molecular bonds, or cross-links, in the collagen.
Is cross-linking right for me?
Patients over the age of 14 who have been diagnosed with progressive keratoconus or corneal ectasia following refractive surgery should ask their doctor about corneal cross-linking.