A Brief Guide to Corneal Cross-Linking (CXL) for the Treatment of Keratoconus
Written by Dr. James Lehmann on 10/5/18
As common as vision problems are, most people expect that their vision will be healthy until they’re older. After all, many of the most popular eye-related illnesses like cataracts tend to develop later in life.
That’s why it can be so shocking for a young person to hear about their keratoconus diagnosis.
The good news is that keratoconus is a treatable condition. In the past few years, the FDA has approved a highly successful keratoconus treatment called corneal crosslinking.
Here’s what you need to know about keratoconus and about this unique treatment.
What is Keratoconus?
Keratoconus is an eye condition that affects your cornea. Your cornea is the dome-shaped, clear tissue at the front of your eye. It’s the part of your eye that focuses light into your eye.
In a typical eye, the cornea is round. However, in a patient with keratoconus, the cornea gradually gets thinner and this causes it to bulge into a cone-like shape. When the cornea is shaped differently, light doesn’t focus correctly in your eye. This leads to blurry vision and can make you more susceptible to light sensitivity or night blindness.
It’s unfortunate, but we don’t know what causes keratoconus so there isn’t a known way to prevent it. It appears to have a genetic link, but it isn’t always a condition families share. Keratoconus is also more common in people with Down syndrome, although researchers don’t know why.
How Keratoconus Progresses
In most cases, keratoconus starts to develop in a patient’s late teens or early 20s. It gradually gets worse over the following years or decades, and it tends to stop progressing by age 40.
While keratoconus doesn’t tend to cause blindness the way most people think of blindness, it can make your vision so blurry that most tasks are difficult. If the condition becomes severe, some patients may need a cornea transplant.
The good news, though, is that corneal crosslinking is an effective way to slow or stop keratoconus’ progression.
What is Crosslinking for Keratoconus Treatment?
Corneal crosslinking, sometimes called CXL, is a way to strengthen the cornea. This stops the thinning and bulging that keratoconus causes.
How Corneal Crosslinking Works
The term “crosslinking” means to form new bonds between molecules, that that’s what CXL does. Corneal crosslinking is a procedure that strengthens the molecular structure of your cornea, protecting you against the progressing effects of keratoconus.
CXL was first performed in 1998 in Germany. However, it finally gained FDA approval in 2016. CXL works because of the reaction between riboflavin (vitamin B2) and precise UVA light. When your eye has enough topical B2 and the right amount of UVA light is applied, it produces new bonds between the collagen fibers in your cornea, creating a strengthening effect.
Two Types of Corneal Crosslinking
There are two basic approaches to CXL: removing an area of epithelial tissue (Epi-Off) or keeping the epithelial tissue intact (Epi-On).
While Epi-On is a less invasive procedure, Epi-Off can provide a more substantial result. Your eye doctor will determine the best option for you based on your keratoconus’ progression and your specific needs.
The Corneal Crosslinking Procedure
Whether or not our doctor starts by clearing epithelial tissue, the next step is to apply riboflavin drops. The riboflavin needs to saturate your corneal tissue to a certain level, which typically takes about 30 minutes.
As the riboflavin saturates, it also helps to protect your lens, retina, and other eye tissues from the effects of the UVA light.
After 30 minutes, your doctor will check to ensure that your corneas have enough riboflavin. When they reach this level, your doctor will use a specialized device to apply targeted UVA light to your eyes. The UVA exposure will last for about 30 minutes, and the doctor will apply more riboflavin every few minutes along the way.
When your procedure is finished, our doctors will rinse away the remaining riboflavin. They will apply a topical antibiotic, a topical anti-inflammatory, and a bandage contact. They will give you instructions about what drops to apply and how to care for your eyes as they heal. If you had an Epi-Off procedure, you’ll keep the bandage contact on for up to five days while your epithelial tissue heals.
After Your Corneal Crosslinking Procedure
For most patients, their vision is worse in the first month or two after their CXL procedure. This is because your eyes are healing, and it shouldn’t worry you. In most cases, by the third month your vision will be back to what it was before the procedure.
Some patients see improvements in their vision after this point, potentially continuing until a year after their procedure. While this can be a great result, keep in mind that the purpose of CXL is to stop your keratoconus from progressing, not to reverse its effects. Don’t expect your vision to improve, but see it as a happy side effect if it does happen.
Overall, CXL has a great success rate. Over 93% of corneal crosslinking patients saw a reduction or a stop in their keratoconus progression. While it doesn’t cure keratoconus, corneal crosslinking is a great way to keep the symptoms to a minimum.
Is Corneal Crosslinking the Right Choice for Your Keratoconus?
Corneal crosslinking has a proven record of success. Especially for patients who get treatment early, it can slow or stop the progression of keratoconus to protect your vision.
Keep in mind that even without CXL, only a fraction of people with keratoconus will develop symptoms severe enough to warrant a corneal transplant. However, depending on how your condition is progressing, CXL can be a great way to keep your symptoms at bay so you may still have adequate vision with glasses or contacts.
At the end of the day, your eye doctor is the only person who can determine if you’re a candidate for CXL or another keratoconus treatment. To find out if it can help you, contact our corneal crosslinking experts for a consultation. If you’re a current patient, schedule your appointment online.