Corneal cross-linking (CXL) is a treatment for patients with keratoconus which can prevent their condition getting worse. CXL is successful in preventing the condition deteriorating in more than 90% of cases. Keratoconus worsens as the cornea weakens. CXL uses ultraviolet light and vitamin B2 (riboflavin) drops to harden the cornea. Together, they cause fibers within the cornea to cross-link – or bond more firmly. This treatment emulates the normal age-related hardening of the cornea, which is known as natural cross-linking
Keratoconus is a progressive thinning of the cornea. The cornea is the clear front window of the eye, which, along with the intra-ocular lens, focuses light on to the retina. The cornea normally is a smooth, round dome-shaped structure; however in keratoconus it becomes very thin and irregular and it starts to protrude from the centre or below the centre like a cone. This causes blurry vision that is often not completely correctable with glasses.
Keratoconus is multifactorial in origin but there is a strong genetic component which makes it more frequent in certain parts of the world or within certain families. . it can also be related to frequent eye rubbing which leads it to be more progressive.
The treatment is recommended only for patients whose scans show that their keratoconus is getting worse, or for those who are at particularly at high risk of their keratoconus deteriorating such as children. 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.
This treatment is minimally invasive and local anesthesia drops are instilled so that the procedure is not painful. Vitamin B2 (Riboflavin) drops are instilled frequently while the ultraviolet light is applied on the cornea for 10-30 minutes. This treatment strengthens the cornea and slows down or prevents the progression of the disease. The treatment aims to improve the vision and the need for glasses or contact lenses will still be required, however some keratoconus cases can improve slightly with the treatment. The corneal cross linkage procedure can be combined with other corneal procedures in parallel or in sequence such as intracorneal ring implant or specific map surface laser.