Corneal Collagen Crosslinking (CXL) is a technique that uses ultraviolet (UV) light and a photosensitizer called riboflavin (liquid vitamin B2) to strengthen the cornea and attempt to reduce the progression of Keratoconus (KCN) or post-LASIK ectasia. The normal cornea retains its shape. In keratoconus or ectasia, the cornea becomes irreversibly thin and bulges outward, leading to impaired visual acuity. The condition is thought to be progressive, meaning there is a high chance it will continue to worsen with time. Crosslinking of collagen refers to the ability of collagen fibers to form strong bonds with other fibers. In the cornea, collagen cross-linking occurs naturally with aging, which may be one reason why KCN progression is thought to slow with age.
During the Crosslinking procedure, the patient is first given numbing drops in their eye. A lid separator may be used to hold the eyelids open. Depending on the patient, the epithelial surface cells may be removed. Riboflavin (vitamin B2) drops are used to moisten the cornea until the riboflavin can be seen throughout the cornea. This usually takes approximately 20 minutes.
After the riboflavin is present throughout the cornea, the UV light is applied to the cornea. The UV light portion of the treatment typically lasts about 30 minutes. Various drops and medications are prescribed to assist with the healing process. A soft bandage contact lens may be placed over the cornea to aid in the healing, protecting the vulnerable cornea from wind and dust. The patient is evaluated over the next several months to monitor the healing response. After the procedure, your eyeglasses or contact lenses may not work as well as they used to, because crosslinking may change your prescription. It typically takes 4-6 weeks after the procedure before contact lenses or glasses prescriptions can be prescribed.
Epithelium-Off corneal crosslinking was recently FDA-approved in the United States. Minnesota Eye Consultants offers both the FDA-approved procedure, and a different variation of the crosslinking procedure (which does not remove the epithelium). Please discuss with your surgeon the benefits and risks of each procedure.