Long-term Safety and Efficacy of Corneal Collagen Crosslinking in a Pediatric Group With Progressive Keratoconus: A 7-year Follow-up

Am J Ophthalmol. 2023 Jun:250:59-69. doi: 10.1016/j.ajo.2023.01.012. Epub 2023 Jan 20.

Abstract

Purpose: To assess effectiveness and safety of corneal crosslinking (CXL) to reduce keratoconus (KC) progression and improve visual acuity among children with progressive KC and to analyze the use of 20% dextran-based (Dextran) and 1% hydroxypropyl methylcellulose-based (HPMC) riboflavin.

Design: Prospective, clinical cohort study METHODS: Standard CXL (SCXL) was performed in 74 eyes (58 patients, 45 males, mean age 13.0 ± 2.1 years): 53 eyes with HPMC and 21 with Dextran. Examinations were performed at baseline, 3 and 6 months, and 1, 2, 3, 4, 5, and 7 years of follow-up, including uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), a complete ophthalmologic examination, anterior segment ocular coherence tomography, Scheimpflug corneal tomography, and specular microscopy.

Results: UDVA and CDVA improved at all periods with statistically significant differences in CDVA at 1, 2, and 3 years. Compared with baseline, maximum K (Max K) reduced throughout the 7-year follow-up. Mean thinnest pachymetry (Th Pachy) decreased significantly at 3 months and remained low; in the Dextran group, the Th Pachy mean value returned to baseline 6 months postoperatively. After CXL, 1.5 diopter progression in max K was 1.4% to 14.6% of eyes; worsening was found at 4 to 7 years postoperatively.

Conclusion: SCXL reduced KC progression in children up to 7 years of follow-up and revealed improvement and stability of UDVA and CDVA in 82% of eyes. For visual acuity and KC stability, no statistically significant difference was observed between Dextran-HPMC. The HPMC group showed persistent cornea thinning, raising concerns about its use in SCXL.

MeSH terms

  • Adolescent
  • Child
  • Collagen / therapeutic use
  • Corneal Pachymetry
  • Corneal Stroma
  • Corneal Topography
  • Cross-Linking Reagents / therapeutic use
  • Dextrans / therapeutic use
  • Follow-Up Studies
  • Humans
  • Keratoconus* / diagnosis
  • Keratoconus* / drug therapy
  • Male
  • Photochemotherapy* / methods
  • Photosensitizing Agents / therapeutic use
  • Prospective Studies
  • Riboflavin / therapeutic use
  • Ultraviolet Rays

Substances

  • Photosensitizing Agents
  • polyacrylamide-hydrazide polymer
  • Dextrans
  • Riboflavin
  • Collagen
  • Cross-Linking Reagents