CXL may be most effective in 18- to 39-year-olds

This retrospective study on the long-term outcomes of corneal cross-linking (CXL) for progressive keratoconus found that the procedure provided better functional and morphologic results in patients between 18 and 39 years of age than in other age groups.

Subjects were 400 consecutive eyes of 301 patients treated with corneal CXL for progressive keratoconus between April 2006 and April 2010. The compiled data were stratified and analyzed according to age: younger than 18, 18 to 29, 30 to 39, and older than 40.

After 36 months, BCVA improved significantly in all groups but improved the most (mean reduction of 0.33 logMAR) in the 30- to 39-year-old age group. Morphologic results for this group showed a parallel improvement of refractive, topographic and aberrometric values for up to 36 months of follow-up. Similar to the 18- to 29-year-old age group, pachymetry results showed a significant increase compared with those from month one.

They write that there are no other published reports of keratoconus procedures showing better outcomes for the 18- to 39-year-old age group. One study reported better outcomes in adolescents treated with corneal transplantation, whereas another study showed worse outcomes in pediatric patients. One report from 2008 showed good results of intracorneal ring segments in all of the evaluated age groups.

They write that one explanation for why CXL seems to favor 18- to 39-year-olds while the other procedures don't is that the other techniques aim to replace or remodel the ectatic tissue, while CXL aims to increase the biomechanical stiffness of the tissue. This could lead to the difference in outcome depending on age.