What Physicians Need to Know About Corneal Cross-Linking

As a physician, you want to offer your patients the best available treatment options and put them on a path best suited for their individual needs. For keratoconus patients, that may mean corneal cross-linking to slow or halt the progression of the disease.

While there are different types of cross-linking procedures available, only iLink™ is FDA approved and covered by insurance. Keep reading for important information on the iLink procedure and insurance coverage.

What is Corneal Cross-Linking?

Corneal cross-linking is a minimally invasive, outpatient procedure for the treatment of progressive keratoconus. iLink FDA-approved epi-off cross-linking combines the use of prescription eye drops, Photrexa® Viscous (riboflavin 5’phosphate in 20% dextran ophthalmic solution), Photrexa® (riboflavin 5’phosphate ophthalmic solution), and ultra-violet A (UVA) light from the KXL® System to treat progressive keratoconus and corneal ectasia following refractive surgery. It works by creating new collagen cross-links and leads to the stiffening of the cornea.

Cross-linking illustration.

What Is the Difference Between FDA-Approved & Non-FDA-Approved Cross-Linking?


iLink Cross-Linking

iLink Cross-Linking requires the removal of the epithelium, the outermost layer of the cornea, to assure deep penetration of the prescription eye drops. iLink cross-linking performed with Photrexa® Viscous, Photrexa® and the KXL® System has been rigorously tested and is the only cross-linking procedure approved by the US Food and Drug Administration (FDA).


Epi-On Cross-Linking

Epi-on cross-linking is a procedure where the epithelium is left intact. In the U.S., there are currently no epi-on cross-linking procedures that are FDA approved.

Map of US showing all states have plans that cover cross-linking.

Products That Are Not FDA Approved

The use of any drug(s) other than Photrexa® Viscous and Photrexa® or any device other than the KXL® System for corneal cross-linking is not FDA approved, except as part of an investigational new drug (IND) study.

Current FDA Approved Procedures

iLink cross-linking performed with our Photrexa® Drug Formulations, and KXL® System is the only cross-linking procedure approved by the FDA. The FDA approval letters for our cross-linking products can be found here:

Which Cross-Linking Procedure Will Insurance Cover?

Fortunately, over 95% of the commercially insured population currently has access to the iLink FDA-approved epi-off corneal cross-linking procedure. Major insurers, including Aetna, Cigna, BCBS of MA, are covering the FDA-approved procedure. See below for more details on their positive policies.

Access to Cross-Linking in US infographic.

Cigna: “Conventional, epithelium-off, corneal collagen crosslinking (C-CXL) using a FDA approved drug/device system (e.g., Photrexa® Viscous or Photrexa® with the KXL® System) (CPT Code® 0402T; HCPCS Code J2787) is considered medically necessary for the treatment of progressive keratoconus and corneal ectasia following refractive surgery.”

BCBS of MA: “Currently, the only CXL treatment approved by the Food and Drug Administration (FDA) is the epithelium-off method. There are no FDA-approved CXL treatments using the epithelium-on method.”

Generally, insurance does not typically cover products and procedures that have not received FDA approval, which includes epi-on cross-linking. For example, as part of their evaluation criteria Blue Cross and Blue Shield Association’s Technology Evaluation Center has reinforced that: “1. The technology must have final approval from the appropriate governmental regulatory bodies.”

Patient Resources for Corneal Cross-Linking Insurance Coverage

If your patients have questions or are looking for more information on insurance coverage, you can direct them to Living with KC, our safe and inclusive patient community that supports people on their keratoconus journey. The website has an easy-to-use interactive insurance guide for patients to determine if their insurance covers the procedure. In addition, it lists the insurers that are covering iLink FDA-approved cross-linking and links to their coverage policies.

Moving Forward

Having accurate information with respect to cross-linking can help you determine what treatment option you should be offering to your patients to help them determine their treatment path. If you have any questions or would like additional information on iLink cross-linking with the KXL® System and Photrexa® Drug Formulations, visit our website or contact us for more details.

Similarly, if your patients have additional questions on keratoconus, Living with KC offers resources to find keratoconus communities and networks as well as advocacy groups. There are also patient columns and KC Journeys, which offer patient stories and testimonials.

If you’re interested in reading some stories of patients that have received iLink FDA-approved cross-linking, you can find their keratoconus journeys here.

Using Photrexa® Viscous (riboflavin 5’-phosphate in 20% dextran ophthalmic solution), Photrexa® (riboflavin 5’-phosphate ophthalmic solution), and the KXL® System, the iLink™ corneal cross-linking procedure from Glaukos is the only FDA-approved therapeutic treatment for patients with progressive keratoconus and corneal ectasia following refractive surgery.*1

[Photrexa IFU/p1/col1/para3/lines1-4]


Photrexa® Viscous (riboflavin 5’-phosphate in 20% dextran ophthalmic solution) and Photrexa® (riboflavin 5’-phosphate ophthalmic solution) are indicated for use with the KXL System in corneal collagen cross-linking for the treatment of progressive keratoconus and corneal ectasia following refractive surgery.

Important Safety Information

Corneal collagen cross-linking should not be performed on pregnant women.

Ulcerative keratitis can occur. Patients should be monitored for resolution of epethelial defects. The most common ocular adverse reaction was corneal opacity (haze). Other ocular side effects include punctate keratitis, corneal striae, dry eye, corneal epithelium defect, eye pain, light sensitivity, reduced visual acuity, and blurred vision.

These are not all the side effects of the corneal collagen cross-linking treatment. For more information, go to obtain the FDA-approved product labeling.

You are encouraged to report all side effects to the FDA. Visit, or call 1-800-FDA-1088.

*Photrexa® Viscous and Photrexa® are manufactured for Avedro. The KXL® System is manufactured by Avedro. Avedro is a wholly owned subsidiary of Glaukos Corporation.


1. Photrexa [package insert]. Waltham, MA: Glaukos, Inc. 2016