Corneal Cross-Linking (CXL): Everything You Need to Know

Have you heard recently about corneal cross-linking (CXL)? Many keratoconus patients undergo this procedure. What is it, why do keratoconus patients turn to it, and is it a definitive cure for keratoconus? Read on for the answers.

What Is Corneal Cross-Linking?

The clinical term is corneal collagen cross-linking — commonly known as CXL. It is a procedure used to strengthen the cornea, and is sometimes referred to as keratoconus stabilisation, because it is most often performed in keratoconus patients whose corneas are weak, thin and irregular in shape. The procedure was first performed in 1998, after which approvals to use it as a treatment option for keratoconus followed in country after country.

How Is Corneal Cross-Linking Performed?

CXL is a quick procedure performed in around an hour. The surgeon uses ultraviolet light and an eye drop to strengthen the collagen fibres in the cornea. First, your surgeon applies riboflavin (vitamin B2) eye drops to the eye, then directs a specific type of ultraviolet light directly onto the cornea. The drops contain riboflavin, which acts as a photosensitiser and enables the cross-linking reaction. The procedure forms new collagen cross-links — these can shorten and thicken the collagen fibres, producing a stronger, stiffer cornea.

Who Needs Corneal Cross-Linking?

1- Keratoconus patients — these are the primary candidates for CXL, because the cornea in keratoconus is weakened and unresponsive to standard treatments.

2- Patients with severe corneal infections — in some cases, CXL is used as part of management.

3- Patients with severe corneal ulcers.

Benefits of Corneal Cross-Linking

• Strengthens weakened corneal fibres and restores corneal stiffness.
• Slows progression of keratoconus and the worsening refractive error that comes with it over time.

The reason is that the interaction between ultraviolet light and the riboflavin (vitamin B2) in the cornea strengthens the weakened corneal fibres.

Possible Side Effects of Corneal Cross-Linking

Mild eye discomfort.

Blurred vision.

Light sensitivity.

In rare cases, complications such as corneal ulceration or scarring can occur.

These symptoms typically fade quickly, after which patients begin to feel the actual benefits of the procedure.

Is Corneal Cross-Linking a Definitive Cure for Keratoconus?

This question comes up constantly — and the honest answer is no.

CXL is not a definitive cure for keratoconus, but it slows disease progression by strengthening the corneal fibres.

Who Is the Best Doctor for Corneal Cross-Linking?

Corneal disease typically requires a specialist surgeon who is up to date with the latest techniques and clinical literature. We recommend Dr. Ahmed Shaarawy.

Dr. Shaarawy is a corneal surgery specialist with a PhD and fellowship from the Devers Eye Institute, USA.

– He was the first surgeon to perform endothelial keratoplasty in Egypt and Iraq, and the first to discuss the technique in the Arab world.

– He has a wide and distinguished record of successful operations across the Arab world, alongside an active research profile, having published novel approaches to corneal disease.

Frequently Asked Questions About Corneal Cross-Linking

Is the procedure painful?

The procedure itself is not painful, although some discomfort is common during the healing phase — typically not immediately after treatment. A bandage contact lens is placed on the eye to protect the freshly treated area once the anaesthetic drops wear off.

What can a keratoconus patient expect from CXL?

Based on the published literature, keratoconus progression rates of about 1.4 D to 1.7 D per year before CXL fall to about 0.6 D in 12 months in patients who undergo cross-linking. Individual results vary, but in aggregate the procedure substantially limits progression of keratoconus.

Is CXL performed on both eyes on the same day?

If you have keratoconus in both eyes and both require cross-linking, each eye is generally treated on a separate day.

Is cross-linking right for me?

Patients who have been diagnosed with keratoconus should ask their ophthalmologist whether they are appropriate candidates for corneal cross-linking.

Post-Operative Instructions

Use the eye drops your surgeon has prescribed, regularly, to avoid dry eye.
Avoid eye rubbing for one week after surgery.
Avoid getting water in the eye for one week after surgery.
Avoid eye makeup during the first week after surgery.
Avoid strenuous activity until the eye has fully recovered.
Wear sunglasses when outdoors, due to the light sensitivity that may occur in the days after the procedure.
Avoid dusty or smoky environments.

Finally, if you have keratoconus, only undergo this procedure with a specialist surgeon, and don't expect CXL to replace a corneal transplant — the latter remains the definitive option for advanced disease. To learn more about corneal disease, follow our blog. To book a consultation, contact us today.