14 Corneal Collagen Cross-Linking for KeratoconusCorneal Collagen Cross-Linking for Keratoconus

Keratoconus Collagen cross-linking (CXL) Bilateral corneal ectatic disorder Keratoconus is a bilateral corneal ectatic disorder characterized by progressive thinning and steepening of the cornea. This results in high amounts of irregular astigmatism and can progress to scarring, hydrops, and perforation—three outcomes requiring corneal transplantation for visual rehabilitation. Typically, the onset of keratoconus is at puberty, and it can progress until the fourth decade of life. However, there are several reports of keratoconus presenting at even younger ages. Patients diagnosed at younger ages have a significantly higher risk and pace of keratoconus progression, lending to a seven-fold higher risk of requiring corneal transplantation compared to adults. Although optical symptoms may be addressed with refractive correction, corneal collagen cross-linking (CXL) is the only definitive intervention to prevent disease progression. This chapter reviews CXL using the Dresden protocol, currently the only protocol approved by the United States Federal Drug Administration (FDA) for the treatment of keratoconus.