Dramatic Reduction in Corneal Transplants for Keratoconus 15 Years After the Introduction of Corneal Collagen Crosslinking

Cornea. 2024 Apr 1;43(4):437-442. doi: 10.1097/ICO.0000000000003401. Epub 2023 Oct 18.


Purpose: The aim of this study was to investigate the effect of the implementation of corneal collagen crosslinking (CXL) on the frequency of corneal transplants among patients with keratoconus (KC) in the same region.

Methods: Before the introduction of CXL in 2007, 55 primary corneal transplants had been conducted in patients with KC (2005 and 2006) at the Department of Ophthalmology, Oslo University Hospital, Norway. We collected data from our corneal transplant registry for 2021 and 2022. The primary outcome was the number of corneal transplants performed in patients with KC. Age, sex, visual acuity (logarithm of the minimal angle of resolution), KC stage according to the Amsler-Krumeich classification system, and steepest keratometry reading (maximum keratometry, Pentacam, HR) were recorded. Furthermore, we registered the annual number of CXL treatments conducted from 2007 to 2022.

Results: A total of 352 corneal transplants were performed in 2021 and 2022. Among them, 11 (3.1%) were transplants for patients with KC. All included patients were male; further, 90.1% and 9.1% of the patients were graded stages 4 and 3, respectively. The mean maximum keratometry was 79.0 diopter (range 61.0-109). The mean best-corrected visual acuity (logarithm of the minimal angle of resolution) was 1.3 (range 0.2-3.0). In 2021 to 2022, 431 CXL treatments were performed.

Conclusions: There was a significant decrease in the number of corneal transplants performed in patients with KC 15 years after the introduction of CXL. This indicates that the availability of CXL treatment over many years may considerably reduce the need for keratoplasties in this group of patients.

MeSH terms

  • Collagen / therapeutic use
  • Corneal Topography
  • Corneal Transplantation*
  • Cross-Linking Reagents / therapeutic use
  • Female
  • Humans
  • Keratoconus* / drug therapy
  • Keratoconus* / surgery
  • Male
  • Photochemotherapy*
  • Photosensitizing Agents / therapeutic use
  • Riboflavin / therapeutic use
  • Ultraviolet Rays


  • Photosensitizing Agents
  • Cross-Linking Reagents
  • Collagen
  • Riboflavin