Research progress in corneal cross-linking agents.

Corneal collagen cross-linking with UVA-riboflavin is currently the only method for preventing the progression of keratoconus from the pathological perspective. Topical application of a direct cross-linking agent is now attracting widespread attention in clinical settings. This article reviews the research progress in the application of indirect or direct cross-linking agents (e.g., riboflavin, glucose, ribose, glutaraldehyde, formaldehyde, glyceraldehyde, short chain aliphatic β-nitro alcohol, and genipin) in the treatment of corneal diseases and analyzes the cross-linking efficacy, toxicity, and merits and disadvantages of each cross-linking agent, providing clinical information for further studies.