Corneal Cross-Linking: Treating Eyes with UV

A discussion of any benefits of UV exposure seems contrary, particularly at this time of year when, as eye care providers, we are ever diligent in advising patients on proper protection from its many clinically proven harms. However, with the FDA’s recent announcement, approving a procedure which uses a combination of UVA and riboflavin in the treatment for certain corneal disorders, a closer look at a therapeutic use of UV for the eye poses an interesting contrast.

Firstly, it should be noted that in Canada, we are fortunate that this procedure known as ‘corneal cross-linking’ has been in use helping patients as early as 2008. This procedure targets the cornea (the transparent front surface of the eye) where certain diseases can cause progressive thinning, creating blurred vision, distortions and can ultimately result in the need for corneal transplant.

Keratoconus is one of these conditions and has been one of the leading indications for corneal transplants for the last 3 decades. Corneal cross-linking is also now used to treat certain post-LASIK complications (corneal ectasia) where excessive thinning results in corneal instability and the potential need for transplant as well.

The technique itself involves the use of a device which specifically directs UVA to a cornea that has been saturated with photo-sensitizing riboflavin (vit. B2) solution. The combination of UVA exposure and riboflavin serves to increase bond formations in the collagen fibrils of the cornea leading to an increased rigidity or “stiffness” of the tissue itself.

I recently spoke with Victoria’s Dr. Ritenour, a corneal surgeon who has been working with corneal cross-linking for many years, first in Toronto and now here on the island. He reports that with early diagnosis, the procedure can provide 98% stabilization in what is otherwise a progressive condition. Additionally, joint treatment approaches here in BC, such as with the addition of laser PRK procedure, are now being employed to both halt the underlying disease progression and further improve visual outcomes. For Dr. Ritenour, corneal cross-linking ‘has changed the paradigm for the treatment of corneal disorders like keratoconus”

In the past, corneal transplants have at times lead to a visual recovery for patients that was prolonged and/or unsatisfactory. Therapeutic treatment utilizing a combination of UV and riboflavin in the form of corneal cross-linking has led to a ‘brighter’ solution for affected patients and…..the future of vision.