{
  "abstract": "Objective To find out if delays longer than 12 weeks between listing and treatment for epithelium-off corneal collagen cross-linking (CXL) are linked to noticeable progression of keratoconus, especially concerning the anterior corneal curvature parameters.Background Keratoconus is a progressive disorder that causes the cornea to bulge. It is important to perform CXL on time to stop the mechanical decline. Pressures in the NHS for elective care often result in longer waiting times. However, there is little evidence on the structural changes in the cornea during these delays. Understanding how waiting time affects outcomes is vital for improving service delivery and preventing unnecessary worsening.Methods We conducted a retrospective audit of 77 eyes from 60 patients with keratoconus who received epi-off CXL at James Cook University Hospital from May 2022 to December 2024. We recorded Pentacam AXL parameters, which included anterior curvature (Kmax, K1, K2), posterior curvature (K1 back, K2 back), and pachymetry at the time of listing and on the day of surgery. We divided the eyes into Group A (≤12-week wait; n=40) and Group B (>12-week wait; n=37). We used paired-samples t-tests (α=0.05) and Cohen’s d to measure changes within each group.Results Group A showed very little anterior progression, with a small but significant increase in Kmax (+0.29 D, p=0.016). Group B exhibited much greater steepening, with Kmax increasing by +0.85 D (p=0.013), along with significant increases in K1 (+0.58 D, p=0.026) and K2 (+0.44 D, p=0.028). Changes in posterior curvature were small and mostly non-significant. Pachymetric parameters displayed limited sensitivity to treatment delays.Conclusion Waiting more than 12 weeks for CXL is linked to clinically significant anterior corneal progression. Setting a maximum wait time of 12 weeks and prioritizing high-risk cases may help reduce worsening before surgery and improve long-term structural outcomes.",
  "authors": [
    {
      "affiliations": [
        "James Cook University Hospital, Middlesborough, UK"
      ],
      "name": "Mohib Naseer"
    },
    {
      "affiliations": [
        "James Cook University Hospital, Middlesborough, UK"
      ],
      "name": "Muhammed Hegab"
    },
    {
      "affiliations": [
        "James Cook University Hospital, Middlesborough, UK"
      ],
      "name": "Trushar Patel"
    }
  ],
  "title": "OP4 Impact of delayed treatment on disease progression of patients with keratoconus listed for collagen cross-linking –CXL",
  "uid": "b1165f63-4737-5d20-8819-26a772c53e68"
}