Transepithelial accelerated versus conventional corneal collagen crosslinking in patients with keratoconus: a comparative study

Purpose: To systematically compare the efficacy of transepithelial accelerated corneal collagen crosslinking (TE-ACXL) with conventional corneal collagen crosslinking (C-CXL) in patients with progressive keratoconus. Methods: Eyes of patients with progressive keratoconus who were treated with C-CXL (3 mW/cm(2) for 30 minutes) were compared with those who underwent TE-ACXL (6 mW/cm(2) for 15 minutes). Best-corrected visual acuity (BCVA), keratometry values, corneal thickness, and topometric indexes were compared before CXL, and at 2 months, 6 months, and 12 months postoperatively. Results: The study enrolled 26 eyes of which 16 had TE-ACXL and 10 had C-CXL. Both groups were comparable at baseline and 12 months in terms of BCVA (P=0.16 and P=0.57), Kmax (maximum keratometry) (P=0.31 and P=0.73), pachymetry (P=0.75 and P=0.37), index of surface variance (ISV) (P=0.45 and P=0.86), index of vertical asymmetry (IVA) (P=0.26 and P=0.61), and index of height decentration (IHD) (P=0.27 and P=0.86, respectively). We did not observe significant differences between preoperative and 12-month postoperative readings in within-group analysis: Delta Kmax (TE-ACXL, -2.13 +/- 5.41, P=0.25 vs C-CXL, 0.78 +/- 1.65, P=0.17), Delta pachymetry (TE-ACXL, 4.10 +/- 14.83, P=0.41 vs C-CXL, -8.90 +/- 22.09, P=0.24), Delta ISV (TE-ACXL, -8.50 +/- 21.26, P=0.24 vs C-CXL, 3.80 +/- 12.43, P=0.36), Delta IVA (TE-ACXL, -0.12 +/- 0.31, P=0.26 vs C-CXL, 0.03 +/- 0.18, P=0.61), and Delta IHD (TE-ACXL, -0.03 +/- 0.07, P=0.18 vs C-CXL, -0.01 +/- 0.03, P=0.88). Conclusion: Both TE-ACXL and C-CXL were similarly effective. Further follow-up is required to determine whether these techniques are comparable in the long-term.