Cross-linking (CXL)
Corneal cross-linking is a procedure that strengthens the structure of the cornea and stops the progression of keratoconus. The method is based on a chemical reaction between riboflavin (vitamin B2) and ultraviolet light, which creates new bonds between collagen fibres in the stromal matrix, making the cornea firmer and more stable.
When is it needed?
Cross-linking is recommended for patients diagnosed with keratoconus in a progressive stage, where the cornea continues to thin and change shape. The procedure is most effective in the early and middle stages of the disease, before changes have advanced to the point of requiring corneal transplantation.
How is it performed?
The standardised Dresden Protocol is used - a three-step procedure:
Epithelium removal - The surface layer of the cornea (epithelium) is gently removed to allow riboflavin to penetrate into the deeper layers.
Riboflavin application - Riboflavin (vitamin B2) drops are applied to the cornea over 30 minutes until uniform saturation of the stromal tissue is achieved.
UV light exposure - The cornea is exposed to a controlled dose of ultraviolet light (UVA), which activates the riboflavin and triggers the formation of new covalent bonds between the collagen fibres.
The procedure is performed under local anaesthetic drops and is painless.
What to expect?
After cross-linking, patients may experience mild irritation and increased light sensitivity for a few days while the corneal epithelium heals. Wearing protective lenses as advised by the doctor and regular follow-up appointments are recommended.
Note for patients: Cross-linking does not restore already lost visual acuity - the goal is to stop further progression of the disease. Many patients do, however, notice some improvement in vision in the months following the procedure.
Results are monitored with the Oculyzer, which allows precise measurement of corneal shape and thickness at every follow-up.
Cross-linking (CXL) at Milmedic Clinic is performed by an experienced team of ophthalmologists led by Prof. Dr Miroslav Vukosavljević, Prof. Dr Mirko Resan, and Dr Elisaveta Stanić.
Frequently asked questions
How long does the entire procedure take?
The procedure itself takes approximately one hour - 30 minutes of riboflavin application followed by UV light exposure. Total time in the clinic, including preparation and the post-procedure check, may be somewhat longer.
Can cross-linking be performed on both eyes on the same day?
Under the standard protocol, cross-linking is performed on one eye, with the second eye treated in a separate visit. This allows for a safer recovery and assessment of results before approaching the second eye.
Can I have refractive surgery if I have keratoconus?
Laser correction is not advisable in keratoconus, as the laser further thins an already weakened cornea and may accelerate disease progression. For patients with keratoconus, the priority is corneal stabilisation with cross-linking; the refractive error is then corrected with contact lenses or other methods that do not remove corneal tissue.
Stop corneal changes in time.
Our team will assess whether you are a candidate for cross-linking and explain all the next steps.