Continued Long-Term Flattening After Corneal Cross-Linking for Keratoconus

Abstract

After corneal cross-linking (CXL), remodelling of the stroma causes corneal flattening and regularisation of the corneal shape. CXL can cause a progressive topographic improvement with an associated hyperopic refractive change throughout the follow-up period. Besides flattening due to scars and intense early flattening, a third entity of excessive continuous flattening can be observed after CXL. Probably variable mechanisms contribute to the outcome of excessive flattening, but the pathophysiology is still unclear. Excessive flattening is more likely to occur in corneas that present signs of more severe disease, topographically represented by steeper corneas. After entering the hyperopic domain, continuous long-term flattening after CXL can be considered a late-onset complication of CXL.