When Paediatric Corneal Cross Linking Does Not Work: Why And When?

To report our 4-year outcomes on repeat corneal collagen cross-linking (CXL) on paediatric patients with Keratoconus (KC) progression after primary treatment. We will perform a systematic review on failure of CXL in children.

Corneoplastic Unit at Queen Victoria Hospital, East Grinstead, UK

We conducted a retrospective analysis of all patients with KC (age <18 years old) who underwent both primary and redo-CXL between Nov 2010 to July 2018 at the Queen Victoria Hospital, East Grinstead, United Kingdom. Progression of KC was based on the presence of an increase (≥1.5 D) in K values (Km or Kmax), reduced VA one or more lines, or a change in refractive spherical equivalent of >1.0 D. Primary and redo CXL were performed using standard or accelerated protocol. Outcome measures were pre- and post-op best corrected visual acuity (BCVA), maximum keratometry (Kmax), average keratometry (Km), spherical equivalent (SE).

135 patients underwent primary CXL, 6 patients (4.4%) (5M: 1F, mean age 15 ranged 14-16), with documented KC progression underwent repeat CXL at mean 18.5 months ( 8- 39months) following first treatment. Five (83.3%) reported history of atopy and eye rubbing. Mean pre-op BCVA was 0.24 logMAR (range 0.1 to 0.6), mean Kmax 60.84±6.95D (Kmax ≥ 53D in 8 eyes), Km 48.4±3.2D and SE -4.5±2.13D. 3 eyes had accelerated CXL. Two eyes had further progression underwent corneal transplantation. BCVA, Kmax, Km and SE of the remaining 7 eyes remained stable or improved up to 4-year with no complications. 4 of 7 eyes had intracorneal ring segments/ phakic IOL shortly before or within 2 years of repeat CXL.

 

4.4% of paediatric KC patients had repeat CXL within first 3 years of primary treatment. 22% had further KC progression despite repeat CXL. Males 14-16year-old, history of atopy and eye rubbing at risk of CXL failure. This group is also more likely to require additional procedures such as corneal transplantation or visual rehabilitation surgery.