What is CrossLinking?
Be Eye Wise and know that CrossLinking, or CXL, is used to increase the rigidness of the cornea’s surface by inducing additional cross-links within or between collagen fibers. By using UV-A light, riboflavin and photomediator, CXL can help slow, stabilize and perhaps even reverse the progression of corneal ectasia and keratoconus.
The cornea is the clear, outer layer of your eye. The middle, or stromal layer, is the thickest part of the cornea. It is made up of mostly water and a protein called collagen. Collagen makes the cornea strong and flexible. It also helps the cornea keep its round, regular shape. This healthy cornea focuses light so you can see clearly.
Some diseases change the middle layer of the cornea. The cornea gets thinner and weaker. This thin cornea bulges into an irregular, cone shape. Your vision may be blurry, and your eyes may be bothered by bright lights. The cornea disease may get worse over time. The medical name for this is corneal ectasia, and there are two types.
- Keratoconus – the cornea starts to thin out and eventually bulge into a cone-like shape, due to the natural aging and changing of your eyes/cornea. Older children, teenagers, and young adults may get this.
- Post-surgery Ectasia – The other type starts after eye surgery such as LASIK (post-refractive ectasia). As a result, vision may become hazy and distorted, making everyday tasks like reading and driving difficult.
The CrossLinking Process
The goal of corneal cross-linking is to make the middle layer (Stromal) stronger. There are three basic steps:
- Dr. Berestka will numb your eye with drops and then gently remove part of the outer layer of your cornea
- Dr. Berestka will then soak your eye with special vitamin eye drops (riboflavin) for 10 minutes.
- Dr. Berestka will shine a special ultra-violet (UV) light on your eye for another 5-10 minutes and keep adding drops. The vitamin eye drops and UV light work together to make the collagen stronger by forming crosslink into the collagen. The cornea becomes stiffer and stronger.
Corneal collagen cross-linking is the only method designed to stop the progression of keratoconus. In fact, it is the preferred method for targeting the stromal instability. As a popular treatment worldwide, patients will experience the expected reduction in the need for donor keratoplasty.
The goal of CXL is to stop the cornea from getting thinner, weaker, and more irregular in shape. But CXL cannot make your cornea normal in shape again. CXL may keep your vision from getting worse and stop the disease process. Sometimes, your vision may improve. In very rare cases, your eye may start getting weak again. If it does, you may need another CXL treatment or another type of cornea surgery.
While the CXL procedure does not cure keratoconus, it aims to stop the progression of the condition and help prevent further damage to the cornea and the need for a corneal transplant. CXL does not treat near or far sightedness and the need for glasses or contacts will still be needed.
Here are some of the most common or serious risk and side effects from the procedure:
Pain: You will probably have pain and be sensitive to light for a few days. You may not be able to drive or work for up to a week after your procedure.
Infection: You could get an eye infection from the surgery. The infection might cause your cornea to scar and make your vision worse. You will get a prescription for eye drops to help prevent an infection. If you had an eye infection called HSV (herpes simplex virus) in the past, it could come back.
Vision problems: Your vision will be poor for a few days or weeks. This poor vision may last longer if you have an infection or your eye does not heal well. You may need to wear contact lenses for up to 6 months after your procedure. Your vision may stay this way.
Changes to your cornea: Your cornea might not heal well, or it might take a long time to heal. It could become cloudy instead of clear (corneal scarring).
Continuous corneal changes: Your cornea may keep changing shape for many months. You may need to get new glasses or contact lenses while the shape is changing, and again after the shape stops changing.
While rare, CXL may not help: You may need more than one CXL treatment. Your cornea could get weak and thin again, or more irregular. If it does, you may need another CXL treatment or another type of cornea surgery.
Are there other options?
There are other ways to treat your weak cornea. Dr. Berestka will talk to you about which treatment would work best for you.
- Glasses and special contact lenses. You may be able to wear glasses and special contact lenses to improve your vision. However, they do not treat or stop your eye problem. So if the cornea keeps getting thinner and weaker, glasses or contact lenses may not be enough.
- Your ophthalmologist could put a small, clear plastic insert inside your cornea (corneal ring segments).
- Some people may need corneal transplant surgery.
Be Eye Wise. Because the more you know, the better you see.