Skip to main content

Evidence to Improve Care

Collagen Cross-Linking Using Riboflavin and Ultraviolet-A for Corneal Thinning Disorders


Ontario Health Technology Advisory Committee Recommendations

  • Based on moderate quality evidence that corneal collagen cross-linking effectively stabilizes the underlying disease process, the Ontario Health Technology Advisory Committee recommends that corneal collagen cross-linking be made available to patients with corneal thinning disorders such as keratoconus that are progressive in nature.

  • As corneal collagen cross-linking does not always improve visual acuity, adjunctive procedures such as intrastromal corneal ring segments may need to be considered for visual rehabilitation and to avoid a corneal transplant.

Read the full OHTAC Recommendation Report



Corneal thinning is an eye disease that occurs when the cornea (the front layer of the eye) gets thinner and bulges out. These changes result in a loss of visual acuity (sharpness of vision) that can make even simple daily tasks difficult. The thinning is believed to be a breakdown of the collagen, the protein fibres that give the cornea its shape, strength and flexibility. Keratoconus is the most common form of corneal thinning disorders.

Vision problems due to corneal thinning usually get worse with time. If glasses or contact lenses no longer help, patients may be referred for corneal transplant as a last option.


Health Quality Ontario Reviews Collagen Cross-Linking for Corneal Thinning Disorders

Collagen cross-linking is a relatively new treatment for some types of corneal thinning, such as keratoconus. The procedure involves applying riboflavin (vitamin B) drops to the eye and then exposing the eye to ultraviolet-A light. The treatment is intended to strengthen the cornea and prevent further thinning and bulging.


Collagen Cross-Linking Using Riboflavin and Ultraviolet-A for Corneal Thinning Disorders: An Evidence-Based Analysis (PDF)
November 2011


Use of this site, and the interpretation of the information contained here, is subject to important terms and conditions. Use of this site and information except in accordance with these terms and conditions is expressly prohibited.


The Ministry of Health and Long-Term Care has accepted this recommendation.

The Ministry of Health and Long-Term Care has provided the following response: This procedure is currently implemented at one location and the Ministry will be looking to evidence from this pilot study to inform expansion.



Let’s make our health system healthier

Join Our Patient, Family and Public Advisors Program

Patients, families and the public are central to improving health quality.


Man smiling

Sign up for our newsletter

Are you passionate about quality health care for all Ontarians? Stay in-the-know about our newest programs, reports and news.

Health Quality Connect - Health Quality Ontario's newsletter - on an iPad and a cell phone