Corneal cross-linking (CXL)

What is CXL?

Corneal cross-linking, or CXL, is an out-patient procedure to strengthen and stabilize a weak, unstable cornea. CXL is most commonly used to treat keratoconus patients or corneal ectasia occurring after refractive surgery. CXL is becoming more and more common around the world and at Finland Eye Center either on its own or as part of the Xtra procedures (see ‘PRK X’, ‘LASIK X’, ‘3D Z LASIK X’ leaflets for further information).

How does CXL work?


CXL creates new collagen bonds to strengthen the cornea by using a combination of ultraviolet light (UVA) and Vitamin B2 (riboflavin). This counteracts the effects of keratoconus and allows preservation of vision if done in early enough. At later stages, CXL can prevent vision deterioration and postpone the need for corneal grafting.

Am I a good candidate for CXL?

CXL is suitable for patients with a confirmed diagnosis of keratoconus or corneal ectasia (clinical examination and corneal topography). The current trend is to treat patients as early as possible, even children, with an upper age limit of around 40 years. Patients with very progressed conditions may be directed towards corneal grafts or other surgical intervention options as the benefits of CXL will be unlikely. 
If you are pregnant or breastfeeding, please inform your doctor.

CXL can also be used for the following more rare conditions:

•    forme fruste keratoconus
•    pellucid marginal degeneration
•    combined procedures (intracorneal rings, phakic IOLs)
•    certain other corneal conditions 

For example, the following patients are not suitable for CXL:

•    herpes simplex keratitis patients
•    riboflavin allergy
•    aphakic eyes
•    some systemic or autoimmune diseases


How is CXL done?

CXL is performed as an out-patient procedure in a treatment room under topical anaesthesia. The procedure can be done for one eye or both at the same time. First, the epithelium (superficial layer of the cornea) is gently removed or a flap is created using the Z LASIK or LASIK method. Riboflavin drops are administered to the exposed cornea after which UVA light is applied. After this, antibiotic eye drops are given and a soft bandage contact lens is placed to help the healing and re-growth of the epithelium. Alternatively, another method is the ‘transepithelial CXL’, which can be done without removing the epithelium. Sunglasses or other protective eyeglasses are recommended during the healing process. Please be assured that the UVA will not harm your eyes when applied properly.

What happens after surgery?

You may experience some discomfort, tearing, sandy eyes and blurred vision for the first few days.
Once the epithelium has grown back (usually 4-7 days) the bandage contact lens will be removed. You may notice a drop in best corrected visual acuity during the first month, but this is normal. The final effects of the procedure should become apparent within the first year. However, it is important to understand that CXL will not cure the condition and it is not a vision improving procedure but a preservation of vision and prevention or postponing of further deterioration and more invasive treatments. Eyeglasses or contact lenses will therefore still be required though the prescription may change.

What are the risks, complications and side effects?

CXL is a safe procedure but as with any operation some complications and risks exist, which you must understand fully before undergoing CXL. Good patient selection reduces the complication rate to about 1% but risks associated with delayed healing time and a potential drop in best corrected visual acuity are possible.

It is essential that you make an informed decision taking into consideration the risks and benefits. 

What is included in the CXL package at Finland Eye Center?

The CXL package includes the bandage contact lens, first week of medication, protective goggles and 3 months of follow-up visits. The package does not include further tools or procedures such as glasses, enhancement CXL, corneal rings, refractive surgery, contact lenses, or corneal grafts.