The aim of our study was to evaluate the efficacy and safety of epi-off conventional and accelerated corneal collagen cross-linking in the treatment of progressive keratoconus in pediatric patients up to 4 years after treatment.
Conventional (standard) CXL epi-off technique was performed in 37 eyes (S-CXL group) and accelerated CXL in 27 eyes (A-CXL group). Refraction, keratometry, cylindrical equivalent, spherical equivalent, slit lamp examination, pachymetry, corneal tomography, anterior segment ocular coherence tomography and visual acuity were performed up to 4 years.
In the S-CXL group: the flat K values decreased from 47.41±3.39 D to 45.36±3.62 D at 4 years (p=0.004); steep K decreased from 51.98±4.11 to 50.21±4.81 D at 4 years (p=0.0078); mean K decreased with 1.99 D at 4 years (p=0.009). In the A-CXL group: the flat K values decreased from 46.97±4.17 D to 44.97±4.24 D at 4 years (p=0.048); steep K decreased from 50.55±4.10 D to 48.75±4.17 D at 4 years (p=0.0287); mean K decreased from 48.79±3.86 D to 46.86±4.11 D at 4 years (p=0.0356). The preoperative mean UCVA in the S-CXL group was 0.8 ±0.23 logMar and improved during the follow-up reaching 0.65 ±0.24 logMar at 4 years (p=0.072). The baseline mean UCVA in A-CXL group was 0.77±0.25 logMar and increased during the follow-up to 0.63 ±0.25 logMar at 4 years (p=0.0039). A similar improvement of BCVA was observed during the follow-up.