Corneal collagen crosslinking (CXL) is an effective treatment to slow down keratoconus (KC) in adults and in pediatric populations, but parents and doctors understandably wonder if treatment alone will stabilize the cornea. A recent meta-analysis investigated the matter.
Of 37 studies (2,078 eyes), the most commonly reported criterion for progression in the KC population treated with CXL was a change in Kmax, Kmean or Ksteep in 78.3% of studies.
The study authors found that “progression occurred in 9.9% of cases in a pooled analysis of 1,508” children, they wrote in their publication on the work. They explain that KC tends to be more advanced at presentation in children than adults, “with a more aggressive course and faster progression, probably because of physiological variability in the structure of the cornea, leading to higher rates of corneal collagen remodeling.”
The fact that children have high rates of progression despite CXL may be due to various factors. “First, CXL may exert less therapeutic efficacy in children because of the higher rate of stromal remodeling in the pediatric population,” the authors suggest. “Second, control of eye rubbing may be much harder to achieve in children. Subsequently, eye rubbing may result in corneal strength reduction, cone-forming deformation, epithelial thinning, abnormal enzyme activity, collagen fibril slippage and keratocyte thinning.”
The authors would like to see quantitative reporting of KC progression in future studies of CXL efficacy in pediatric populations. They also note that an expert consensus suggests that “optimal therapy in children should be as early as possible with CXL, even at the time of diagnosis.”
Achiron A, El-Hadad O, Leadbetter D, et al. Progression of pediatric keratoconus after corneal cross-linking: a systemic review and pooled analysis. Cornea. 2021;00:1-5.