Abstract
Purpose :
To compare outcomes after cross-linking (CXL) for progressive keratoconus (KC) performed in children in 2 different age groups: ≤14 (group I) and >14 ≤18 years (group II).
Methods :
Retrospective evaluation. Fifty-seven eyes were treated with the standard Dresden epi-off protocol and had at least a 1 year follow-up. Pre- and postoperative exams included topography and tomography every year, up to 5 years. Mean age of the entire cohort was 14.7±2.9 years (range, 4-18 years), mean follow-up was 45.7±24.6 months.
Results :
Group I consisted of 23 eyes, group II of 34. Group I included 3 cases in which the fellow eye had a keratoplasty because of hydrops (2) or scarred cornea. In group II keratoplasty had to be performed in one fellow eye because of a very fast progression while CXL had been postponed by the family. There were two cases of progression 3 years after CXL (group I). Preoperatively there were no statistical differences between the 2 groups regarding AvK, spherical equivalent (SE), surface regularity index (SRI), surface asymmetry index (SAI), cylinder, pachymetry at thinnest point and KMax. At one year, the mean differences from baseline did reach statistical significance only with regard to KMax (group I -0.67±1.6D, group II -2.5±1.9D, p=0.001, unpaired t-test). At 5 years, changes in KMax were very similar (-1.7 vs -1.8D), while the change in SE showed a significant myopisation in group I (-2.7D) compared to group II (+1.2D, p=0.04). Pachymetry changes were similar at 1 year (-15.4 and -13.3μm, respectively), while at 5 years group I thinned more –but not significantly- (-40.2 vs -26.5μm).
Conclusions :
Although the results for the entire group are satisfactory, with a stabilisation or even flattening of the cornea, it appears that children 14 years of age or younger have a greater risk for progression. CXL is more effective in children older than 14, showing a flatter cornea at 1 year and lesser tendency to myopisation at 5 years. These findings suggest that there may be a need for repeat-CXL in younger children, or at least an indication to keep them under observation for years after CXL.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.