AIM: To report a two-year's results of iontophoresis-assisted transepithelial corneal cross-linking(I-CXL)for progressive keratoconus.

METHODS: Thirty-four eyes in 24 patients with progressive keratoconus(mean age 21.0±5.6 years; range: 14-32 years)were treated. After 1g/L riboflavin-distilled water solution was administered by iontophoresis-assited(current 1mA)transepithelial method for 5min in total, standard surface UVA irradiation(370nm, 3mW/cm²)was performed at a 1-cm distance for 30min. The best corrected visual acuity(BCVA)measured as LogMAR number, corneal refractive astigmatism, K1, K2, Kmean, Kmax, intraocular pressure, endothelial cell density, the thickness at corneal apex and the thinnest point were measured preoperatively and 2a postoperatively.

RESULTS:At 2a after the procedure, BCVA(LogMAR)improved from 0.32±0.25 to 0.25±0.19(t=2.849, P=0.015). K1 decreased from 47.12±4.33 to 46.06±4.77(t=2.652, P=0.015). K2 decreased from 51.36±5.59 to 50.40±6.16(t=2.121, P=0.047). Kmean decreased from 49.12±4.76 to 48.10±5.25(t=2.663, P=0.015). Kmax decreased from 57.57±8.30 to 55.91±8.14(t=2.398, P=0.026). The corneal apex thickness decreased from 476.90±38.71μm to 454.43±40.86μm(t=2.853, P=0.010). The thinnest thickness decreased from 464.38±39.92μm to 433.86±50.78μm(t=3.485, P=0.002). Corneal refractive astigmatism, intraocular pressure and endothelial cell density did not show significant changes.

CONCLUSION: I-CXL for progressive keratoconus is safe and effective which can prevent deterioration of progressive keratoconus within 2a, but further long-term studies are necessary still.