History of Corneal Cross-Linking.

Abstract

Corneal cross-linking (CXL) has profoundly changed the management of keratoconus and other ectatic corneal diseases. Introduced in the late 1990s, CXL marked the first effective intervention to halt disease progression. This chapter describes the history of CXL, beginning with its conceptual foundations and preclinical studies conducted at the University of Dresden. Early experiments established the efficacy of riboflavin and UV-A light to induce collagen cross-linking, which improved corneal stiffness. Clinical translation followed with the Dresden protocol, demonstrating safety and efficacy. Long-term studies confirm sustained benefits, with advances in accelerated protocols and modifications for thin corneas extending eligibility to more patients. Additionally, CXL has expanded into infectious keratitis treatment and refractive surgery. Emerging innovations, such as customized and two-photon CXL, promise further applications. By examining the milestones in its evolution, this paper highlights the transformative impact of CXL on corneal disease management.