What is collagen cross-linking?

Collagen cross-linking is a new treatment for keratoconus, that uses a photosensitizing agent, riboflavin (vitamin B2) &
ultraviolet light (UVA, 365nm) exposure. In extensive experimental studies (including biomechanical stress & strain
measurements) researchers have demonstrated a significant increase in corneal rigidity / stiffness after collagen cross-
linking using this riboflavin/UVA treatment. The 3 & 5 year results of Dresden clinical study in human eyes has shown arrest
of progression of keratoconus in all treated eyes.Crosslinking treatment of progressive keratoconus: New
Hope. Current Opinion in Ophthalmology.

Corneal collagen cross-linking with riboflavin and UV-A light is a surgical treatment for corneal ectasia such as keratoconus, PMD, and post-LASIK ectasia.

Keratoconus is a disorder of the cornea characterized by progressive thinning and ectasia which results in deterioration of the quality of vision and also the quality of life. As the disease begins in young adults, it affects the most productive years of life. So far there has been no effective way to stop the progression of keratoconus. Current methods such as rigid contact lens, & intracorneal ring segments only the refractive error can be corrected without any effect on the progression of keratoconus. It is estimated that eventually 21% of the keratoconus patients require surgical intervention to restore corneal anatomy and eyesight. A new modality of treatment, based on collagen crosslinking with the help of Ultraviolet A (UVA, 365nm) and the photosensitizer riboflavin phosphate has been described which changes the intrinsic biomechanical properties of the cornea, increasing its strength by almost 300%. This increase in corneal strength has shown to arrest the progression of keratoconus in numerous studies all over the world.

 

How is the treatment done?

The treatment is performed under topical anesthesia. The skin (epithelium) of the surface of the cornea is partially
scratched, followed by application of Riboflavin eye drops for 30 minutes. The eye is then exposed to UVA light for 30
minutes. After the treatment, antibiotic ointment is applied and an eye-pad is worn overnight until the next day when the
surface of the eye has healed. Oral analgesics are required for the first 1 -2 days

Who can benefit from this treatment?

Collagen cross-linking treatment is not a cure for keratoconus, Rather, it aims to  halt the progression of the condition. This
is important to understand. Patients will continue to wear spectacles or contact lenses (although a change in the
prescription may be required) following the cross-linking treatment. The main aim of this treatment is to arrest progression
of keratoconus, and thereby prevent further deterioration in vision and the need for corneal transplantation. However in
advanced keratoconus, wherein the corneal thickness is below 350 microns, this treatment may not be possible. In such a
situation other alternatives such as deep anterior lamellar keratoplasty (DALK) should be considered.

Collagen cross linking C3R/UVX