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 for 30 minutes) were compared with those who underwent TE-ACXL (6 mW/cm 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 (=0.16 and =0.57), Kmax (maximum keratometry) (=0.31 and =0.73), pachymetry (=0.75 and =0.37), index of surface variance (ISV) (=0.45 and =0.86), index of vertical asymmetry (IVA) (=0.26 and =0.61), and index of height decentration (IHD) (=0.27 and =0.86, respectively). We did not observe significant differences between preoperative and 12-month postoperative readings in within-group analysis: ΔKmax (TE-ACXL, -2.13±5.41, =0.25 vs C-CXL, 0.78±1.65, =0.17), Δpachymetry (TE-ACXL, 4.10±14.83, =0.41 vs C-CXL, -8.90±22.09, =0.24), ΔISV (TE-ACXL, -8.50±21.26, =0.24 vs C-CXL, 3.80±12.43, =0.36), ΔIVA (TE-ACXL, -0.12±0.31, =0.26 vs C-CXL, 0.03±0.18, =0.61), and ΔIHD (TE-ACXL, -0.03±0.07, =0.18 vs C-CXL, -0.01±0.03, =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.