Journal Article

Demarcation Line Evaluation of Iontophoresis-Assisted Transepithelial Corneal Collagen Cross-linking for Keratoconus

Françoise Froussart-Maille, Marouen Berguiga, Gabriel Bedubourg, Jean-Claude Rigal-Sastourne, Samantha Bonnel, Benoit De Rivoyre, Damien Sendon

2015

Overview

PURPOSE: To evaluate the visualization and depth of the demarcation line with anterior segment optical coherence tomography (AS-OCT) after iontophoresis-assisted transepithelial corneal collagen cross-linking (CXL). METHODS: This prospective, consecutive, single center, non-randomized clinical study involved 15 eyes of 12 patients with keratoconus who underwent an AS-OCT scan (Spectralis; Heidelberg Engineering, Inc., Carlsbad, CA) to search for a demarcation line and its depth at 1 month after iontophoresis-assisted transepithelial CXL. AS-OCT scan measurements were performed by two independent examiners. RESULTS: No intraoperative or postoperative complications were observed. Kappa coefficient estimation for operator agreement in demarcation line visualization (whether it was visualized) was 70.6%. The corneal stromal demarcation line was identified in 9 eyes (60%) by both examiners. Mean depth of the corneal stromal demarcation line was 246.67 ± 50.72 No intraoperative or postoperative complications were observed. Kappa coefficient estimation for operator agreement in demarcation line visualization (whether it was visualized) was 70.6%. The corneal stromal demarcation line was identified in 9 eyes (60%) by both examiners. Mean depth of the corneal stromal demarcation line was 246.67 ± 50.72 µ m (range: 183 to 339 µ m) for the first examiner and 241.89 ± 62.52 µ m (range: 163 to 358 µ m) for the second examiner. There were no statistically significant differences for the measurements of the paired comparisons between the two examiners ( P = .61). The Pearson correlation coefficient between the measurements was 0.910. CONCLUSIONS: Iontophoresis-assisted transepithelial CXL creates a demarcation line that can be visualized with AS-OCT, which seems less easily distinguishable and shallower than in conventional CXL. However, its depth and visualization seems to be more similar to conventional CXL than transepithelial CXL. [[ J Refract Surg . 2015;31(1):36–40.]

• Publisher: SLACK INCORPORATED
• Subject: Adolescent / Adult / Collagen / Collagen - metabolism / Cornea / Corneal Stroma - metabolism / Corneal Stroma - pathology / Corneal Stroma - surgery / Corneal Surgery, Laser - adverse effects / Corneal Surgery, Laser - methods / Cross-Linking Reagents - therapeutic use / Female / Humans / Iontophoresis / Iontophoresis - methods / Kappa coefficient / Keratitis - etiology / Keratitis - pathology / Keratoconus - metabolism / Keratoconus - pathology / Keratoconus - surgery / Laboratories / Male / Patients / Power supply / Prospective Studies / Statistical analysis / Tomography, Optical Coherence - methods / Visualization / Vitamin B / Young Adult