Transepithelial corneal collagen cross‐linking by iontophoresis of riboflavin

Purpose: To evaluate the effectiveness of transepithelial cornea impregnation with riboflavin 0.1% by iontophoresis for collagen cross‐linking. Material and methods:  Transepithelial collagen cross‐linking by iontophoresis of riboflavin was performed in a series of 22 eyes of 19 patients with progressive keratoconus I–II of Amsler classification. The riboflavin solution was administered by iontophoresis for 10 min in total, after which standard surface UVA irradiation (370 nm, 3 mW/cm²) was performed at a 5‐cm distance for 30 min. Results:  The riboflavin/UVA treatment resulted in a decrease in the average keratometry level from 46.47 ± 1.03 to 44.12 ± 1.12 D 1 year after the procedure. Corneal astigmatism decreased from 3.44 ± 0.48 to 2.95 ± 0.23 D. Uncorrected distance visual acuity improved from 0.61 ± 0.44 up to 0.48 ± 0.41 (LogMAR). Preoperative and postoperative endothelial cell density remained unchanged at 2765 ± 21.15 cells/mm². Conclusion:  Transepithelial collagen cross‐linking by iontophoresis might become an effective method for riboflavin impregnation of the corneal stroma reducing the duration of the procedure and being more comfortable for the patients. Further long‐term studies are necessary to complete the evaluation of the efficacy and risk spectrum of the modified cross‐linking technique.