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 10min in total, after which standard surface UVA irradiation (370nm, 3mW/cm(2)) was performed at a 5-cm distance for 30min. Results: The riboflavin/UVA treatment resulted in a decrease in the average keratometry level from 46.471.03 to 44.12 +/- 1.12D 1year after the procedure. Corneal astigmatism decreased from 3.44 +/- 0.48 to 2.95 +/- 0.23D. 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 +/- 21.15cells/mm(2). 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.