Ratification Date: 27/01/2026

Next Review Date: 01/02/2027

Corneal Collagen Cross-Linking for Keratoconus (Eye treatment to strengthen the cornea)

(Eye Surgery)

 

Threshold

 

Norfolk and Waveney Integrated Care Board will fund Corneal Collagen Cross Linking for Keratoconus on a restricted basis and where there is documented evidence of the following criteria:

 

Referral guidelines:

Ensure that patients have corneal tomography scans and refraction with contact lenses out for >2 weeks (for rigid/scleral) and >1 week (soft lenses). Corneal Cross-Linking patients may struggle without contact lens usage, so allow provisional listing with hospital imaging if necessary.

 

Inclusion criteria for patients to be treated: (1 or more)

  1. Confirmed progression (based on current understanding of Pentacam measurement repeatability limits).
Early KC (Kmax<55D)2

(1 or more)

 Moderate/advanced KC (Kmax > 55D)3

(1 or more)
  • ≥ 0.5 D increase in Kmax over 6 months
  • ≥ 1.0 D over 12 months
  • > 1 D increase K2 or K1 front surface
  • > 0.5 D increase back surface
  • ≥ 10–16 μm decrease in thinnest pachymetry
  • Loss of ≥ 1 Snellen line of CDVA not explained by other pathology
  • New or worsening contact lens intolerance attributable to ectasia
  • ≥ 1.0 D increase in Kmax over 12 months
  • ≥ 1.0 D increase in K1 or K2 (front surface) over 12 months
  • ≥ 0.5 D increase in posterior K2 over 12 months
  • ≥ 16 μm decrease in thinnest pachymetry over 12 months
  • Loss of ≥ 1 Snellen line of CDVA not explained by other pathology
  • New or worsening contact lens intolerance attributable to ectasia
  1. High risk of progression (1 or more)
  • Age < 18 years
  • Age 19-30 years (incl.) AND Minimum thickness < 400 μm
  • Age 19-30 years (incl.) AND Hydrops/graft fellow eye
  • Age <25 years with instability, and patients where the fellow eye is too thin for safe CXL (to avoid risk of monocularisation).
  • Previous acute hydrops in fellow eye
  1. History of progression in referral letter based on serial topography or loss of corrected vision – documentation incomplete AND age < 30 years
  2. Previous LASIK/SMILE/PRK with ectasia.

 

NB.  Patients who are unable to come out of contact lenses prior to corneal tomography and therefore ineligible for f/u in EKC) may be offered CXL on pooled list if they are considered at risk of progression (i.e. age<35 years) with continued follow up in Contact lens clinic.

 

Exclusion criteria

  • Active surface disease
  • Minimum corneal thickness <325um
  • Low-fluence epi-off CXL, contact lens-assisted CXL, or hypo-osmolar riboflavin.

 

Retreatment criteria:

Treatment failure should be considered no earlier than 12 months post-CXL using the same keratometric indices if progression recurs (Kmax, K2, K1).

 

Pachymetry is not a useful indicator of progression post-CXL since corneal thickness measurements may decrease and/or increase up to 24 months after treatment.

 

 

Cases for Individual Funding Consideration

On a case to case basis, patients might be eligible for surgical intervention, in consideration of their exceptionality. The requesting clinician must provide information to support the case for being considered an exception, by submitting an individual funding request.

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