Patient information – external disease and corneal service Corneal cross-linking Corneal cross-linking (CXL) is a treatment for patients with keratoconus which can prevent their condition getting worse. It is successful in more than 90% of cases. After treatment, you will still need to wear spectacles or contact lenses. Your eye will be sore for about one week after the procedure. Although vision is often hazy at first, most patients can resume contact lens wear and return to work after one week. As with all operations, there are risks: CXL is safe, but there is a small chance (about 1 in 30) of worse vision afterwards.
What is CXL? Keratoconus gets worse because the cornea weakens. CXL, also known as C3R, uses ultraviolet light and vitamin B2 (riboflavin) drops to stiffen the cornea. Used together, they cause fibers within the cornea to cross-link – or bond more tightly. This treatment mimics the normal age-related stiffening of the cornea, which is known as natural cross-linking.
Which patients benefit from CXL? The treatment is recommended only for patients whose corneal shape scans show that their keratoconus is getting worse, or for those who are at particularly high risk of worsening keratoconus. Because of natural cross-linking with age, keratoconus usually stops getting worse by the mid-30s, so CXL is not normally required for older patients.
What evidence is there that it works? Collagen cross-linking is the only treatment currently available that appears to stop keratoconus from getting worse. Evidence from three randomised clinical trials one year after CXL showed success in halting keratoconus progression in more than 90% of treated eyes, with more than 45% of eyes also gaining an improvement in corneal shape. Longer term results (up to five years) from a different study suggest a similarly high success rate in preventing keratoconus progression. Vision is better after treatment than before in about 50% of eyes treated with CXL.
and many patients find sunglasses helpful. Your vision will be quite blurred at first, but will clear gradually over the first few weeks. It is normal to experience fluctuating pain within the first two days after surgery. However, if you experience increasing pain three or four days after the procedure this could be indicative of infection and you should visit A&E. Please note that infection is rare, affecting fewer than 1% of patients.
Do I need to take time off work or studies? Yes. You should allow at least one week off while most of the surface healing occurs, or two weeks if your job involves a lot of computer work, and the treatment is being done on your best eye. You will be putting eye drops in every hour for the first day, and then every four hours for the following days. Day to day activities such as watching TV or using a computer will not do any damage to your eye, but you might find it more comfortable to rest with your eyes closed early on. You will be given an appointment the following week to check your eye is healing properly.
What should I do, or not do, after CXL? It is important to put the eye drops in regularly as prescribed. Wash and shower normally, but try to avoid getting water in your eyes. You may exercise, but should not swim before the surface of your eye has healed. We will check your vision in the clinic the week after your procedure to confirm if your vision is good enough to drive. It is normally safe to resume contact lens wear once the eye surface skin layer has healed. This typically happens around the end of the second week after your procedure.
What are the risks of CXL? In general, CXL is very safe, but like all operations your eye needs time to heal and problems do occasionally occur. About 3% of patients will lose some vision in the treated eye as a result of haze, scarring, corneal surface shape irregularity or infection. In most cases, this visual loss is potentially reversible with a corneal transplant. Without CXL treatment, at least 20% of all patients with keratoconus will eventually require a corneal transplant. The risk of transplantation for patients with documented disease progression is probably higher.