Evaluation of corneal stromal demarcation line after two different protocols of accelerated corneal collagen cross-linking procedures using anterior segment optical coherence tomography and confocal microscopy

Purpose. to evaluate the depth of corneal stromal demarcation line using as-oct and confocal microscopy after two different protocols of accelerated corneal collagen cross-linking procedures (cxl). methods. patients with keratoconus were divided into two groups. peschke cxl device (peschke ccl-vario meditrade gmbh) applied uva light with an intended irradiance of 18.0 mw/cm2 for 5 minutes after applying riboflavin for 20 minutes (group 1) and 30 minutes (group 2). one month postoperatively,corneal stromal demarcation line was measured using as-oct and confocal microscopy. results. this study enrolled 34 eyes of 34 patients (17 eyes in group 1 and 17 eyes in group 2). the mean depth of the corneal stromal demarcation line was 208.64 ± 18.41 μm in group 1 and 240.37 ± 18.89 μm in group 2 measured with as oct,while it was 210.29 ± 18.66 μm in group 1 and 239.37 ± 20.07 μm in group 2 measured with confocal microscopy. corneal stromal demarcation line depth measured with as oct or confocal microscopy was significantly deeper in group 2 than group 1 (p < 0.01). conclusion. the group in which riboflavin was applied for 30 minutes showed significantly deeper corneal stromal demarcation line than the group in which riboflavin was applied for 20 minutes. © 2014 engin bilge ozgurhan et al.