Cross-Linking

Cross-Linking at McKnight Eye Centers

Corneal cross‑linking is a treatment designed to strengthen the cornea when it begins to thin or weaken. The procedure uses special eye drops and light to help the corneal tissue become firmer and more stable over time. Its main purpose is to slow or stop the progression of conditions that can cause the cornea to bulge or distort, helping protect vision and reduce the need for more invasive treatments later on.

Cross Linking is a treatment that strengthens the cornea to prevent further thinning or bulging. The most common reason for cross linking is Keratoconus, a condition that causes the cornea to weaken and distort vision. This procedure uses riboflavin (vitamin B2) drops and UV light to stabilize the cornea and help slow or stop the progression of keratoconus.

Congratulations Dr. Dustin McKnight, MD at McKnight Eye Centers and Hunkeler Eye Institute on your #iLink procedure success!

What is KC?

Keratoconus (KC) is a sight-threatening and progressive eye disease. 

In KC, the cornea—the clear, round front part of the eye—becomes weak and thin. Its angle becomes steeper, like a cone, causing blurry or distorted vision. 

Signs and Symptoms of KC

Rubbing Your Eyes Often

Changing Glasses or Contacts Due to Worsening Eyesight

Vision That Cannot Be Fully Corrected With Prescription Eyewear

Blurry Vision

Trouble Seeing at Night

Frequent Headaches

Family History of KC

Why is early treatment vital?

Without treatment, keratoconus can worsen over time and result in significant vision loss. A treatment called corneal cross-linking—which uses prescription eye drops, light, and oxygen to strengthen the cornea—can prevent KC from getting worse and impacting life. Corneal cross-linking results are long lasting.

Prescription glasses and contact lenses do not stop KC from getting worse. Treat KC before it’s too late.

Product Information

What is Epioxa (riboflavin 5’-phosphate ophthalmic solution)?

Epioxa (riboflavin 5’-phosphate ophthalmic solution) is the only FDA-approved, non-invasive, epithelium-on, oxygen-enriched, corneal cross-linking treatment for keratoconus (KC).

Take care of your KC: Early treatment is key to help halt the progression of KC and prevent further vision loss.

  • If left untreated, KC can leave you legally blind
  • Epioxa treatment is different. It’s the only FDA-approved, non-invasive, corneal cross-linking therapy
  • Epioxa treatment is designed for improved comfort and shorter recovery time

Epioxa treatment is a procedure performed by your doctor 1 eye at a time.


Epioxa treatment is non-invasive because it does not remove the outer layer of the cornea, called the epithelium.

How Does Epioxa Work?

Epioxa treatment works using 3 parts

  • Part 1
  • Part 2
  • Part 3
Part 1

Part 1

Light-enhancing Epioxa and Epioxa HD drops are activated by ultraviolet (UV) light to cause the chemical reaction that makes corneal cross-linking take place

Part 2

Part 2

Boost Goggles® provide an oxygen-rich environment, which is required for the corneal cross-linking effect

Part 3

Part 3

A special lamp delivers UV light, which works with Epioxa eyedrops and oxygen to strengthen the cornea and help halt KC

Epithelium-on Epioxa treatment is designed to improve comfort and recovery time.

Epioxa treatment can halt KC progression

Epioxa treatment was compared with placebo (no active treatment) in 2 clinical trials: Trial 1 was for 6 months and Trial 2 was for 12 months.

At the start of each trial, doctors measured the steepness of the cornea’s curvature for each participant to determine the severity of their KC.

At the end of each trial, doctors measured how much the steepness of the cornea curve had changed.

Epioxa clinical trials included nearly 600 eyes in people with KC aged 13 to 55 years old. The safety of Epioxa treatment was proven in 2 clinical trials

The most common side effects were mild and temporary:

• Red eye

• Haze

• Sensitivity to light

• Disruption of surface cells of the cornea

• Eye pain

• Eye irritation

• Watery eyes

• Swelling of eyelid

• Fine white lines in the cornea

• Reduced sharpness of vision

• Dry eye

• Eye inflammation

What to expect after your Epioxa treatment

Contact your doctor immediately if you experience severe pain in the treated eye or any sudden decrease in vision. You may feel some discomfort in the treated eye. Wearing sunglasses may help if you are sensitive to light after treatment. Go home and rest. Do not rub your eyes. Take any medications prescribed by your doctor.

Some people got their second eye treated as early as 1 week after their first eye was treated.

Epioxa FAQs

Is Epioxa covered by insurance?

Check with your healthcare insurance provider. You may pay as little as $0* for Epioxa if you are commercially insured.

*For eligible patients who are commercially insured.

What is Epioxa?

Epioxa is the only FDA-approved, epithelium-on, corneal cross-linking treatment for keratoconus (KC).

How is Epioxa different from other treatments for keratoconus?

Epioxa is the first and only epithelium-on, corneal cross-linking treatment approved by the FDA to treat KC.

Who is eligible for Epioxa?

Epioxa is approved to treat KC in adults and pediatric patients aged 13 years and older.

Is Epioxa safe and effective?

Yes, the safety and efficacy of Epioxa were studied in 2 prospective, multicenter, randomized 2:1 procedure/placebo-controlled clinical trials, and was approved by the FDA for the treatment of keratoconus in adults and pediatric patients aged 13 years and older.

For complete information, please see full Prescribing Information.

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Advanced Cross-Linking for Stronger Corneas