Epithelium-off corneal collagen cross-linking versus transepithelial cross-linking for pediatric keratoconus.

PURPOSE: To compare efficiency and safety of epithelium-off corneal cross-linking (CXL) and transepithelial cross-linking (TE-CXL) in pediatric patients with progressive keratoconus.

METHODS

Uncorrected and corrected visual acuity, corneal topography and pachymetry (Pentacam; Oculus Pentacam), and in vivo confocal microscopy (HRT II, Rostock Cornea Module, Heidelberg Engineering, Heidelberg, Germany) were evaluated at baseline and at 3, 6, and 12 months.

RESULTS

In the epithelium-off CXL group (19 patients, 23 eyes; mean age, 14.75 ± 2.1 years), a significant improvement at month 12 was present for Kmax [-1.11 diopters (D), P = 0.01], Kmin (-3.2 D, P = 0.001), mean K (-1.47 D, P = 0.01), surface asymmetry index (-0.64 D, P = 0.001), inferior-superior symmetry index (-0.54 D, P = 0.01), index of height asymmetry (-2.97, P = 0.03), and anterior elevation at the thinnest location (-2.82 D, P = 0.01) and at the apex (-2.27 D, P = 0.01). Postoperative corneal edema lasted 3 months in 16 eyes (69.5%) and more than 6 months in 2 eyes (8.7%). In the TE-CXL group (10 patients, 14 eyes; mean age, 15 ± 4.2 years), a significant improvement at month 12 was present for Kmax (-1.14 D, P = 0.02), Kmin (-2.04 D, P = 0.01), mean K (-1.63 D, P = 0.01), surface asymmetry index (-0.86 D, P = 0.001), inferior-superior symmetry index (-0.55 D, P = 0.001), index of height asymmetry (-2.95, P = 0.01), and anterior elevation at the thinnest location (-2.96 D, P = 0.01) and at the apex (-2.19 D, P = 0.01). No postoperative corneal edema after TE-CXL was observed. Changes at month 12 from baseline were not significantly different between the 2 groups (P > 0.05). TE-CXE was significantly less painful than epithelium-off CXL.

CONCLUSIONS

In pediatric patients with progressive keratoconus, TE-CXL was less painful, provided similar effectiveness and fewer complications than epithelium-off CXL at 12-month follow-up.