Individual Risk Assessment and Prognostication of Outcomes After Corneal Cross‐Linking

<b>Background and Objective:</b> Corneal collagen cross-linking (CXL) is a treatment which arrests keratoconus (KC) progression, but its effectiveness differs radically among patients. Herein, we report preoperative diagnostic findings that reflect CXL outcomes and allow physicians to prognosticate treatment efficiency. <b>Methods:</b> In a medical centre, we retrospectively analysed pre- and postoperative data about 107 patients (112 eyes) treated with CXL from January 2018 to December 2022. Exclusion criteria were age below 16 years, a corneal thickness below 400 microns, severe dry eye, other corneal diseases/infections, re-CXL, pregnancy and missing follow-up examinations. All the subjects (79 males and 28 females) were followed for a minimum of 4 and a maximum of 40 months. The study dataset was comprised of 796 cases of clinical assessment, pachymetry, visiometry, refractometry and topography examinations. With these data, we modelled maximum anterior keratometry (<i>K</i> _max) and curvature power of the flat and steep meridians of the corneal anterior surface (<i>K</i> ₁ and <i>K</i> ₂). <b>Results:</b> Two years after the invasion, corneal curvature coefficients decreased progressively. Then, they remained stable for four months and rose afterwards. In the most accurate <i>K</i> ₁, <i>K</i> ₂ and <i>K</i> _max models, the proportion of mean absolute error to the range of values was 1.72, 3.66 and 2.37%, respectively. Pronounced corneal thinning, low best-corrected visual acuity and high <i>K</i> _max levels predict unfavourable outcomes. <b>Conclusions:</b> The high accuracy of the models advocates for a personalised approach to candidate selection for CXL.