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

Abstract

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.

Conventional versus accelerated corneal collagen cross‐linking in the treatment of keratoconus

“…Similar to our observation, studies comparing the demarcation line depth between conventional and accelerated CXL showed that the demarcation line was consistently deeper with the former protocol . Kymionis et al .…”

“…Similar to our observation, studies comparing the demarcation line depth between conventional and accelerated CXL showed that the demarcation line was consistently deeper with the former protocol. [28][29][30] Kymionis et al noted that a 10-min treatment with 9 mW/cm 2 resulted in a demarcation line that was less deep compared to the standard protocol. 29 In a latter study, Kymionis and his co-workers developed a modified 9 mW/cm 2 -accelerated CXL protocol by increasing the treatment time to 14 min resulting in 40% increased of total illumination energy.…”

Superior outcome of corneal collagen cross‐linking using riboflavin with methylcellulose than riboflavin with dextran as the main supplement

“…In a study comparing dextran–riboflavin soaking time, deeper demarcation lines were found after 30 min than 20 min (Ozgurhan et al. ). Due to a higher intracorneal concentration of riboflavin with time, this probably means that a higher intrastromal concentration of riboflavin causes a deeper effect (Ehmke et al.…”

Morphologische Hornhautveränderungen nach Crosslinking bei Keratokonus

“…Trotz der bereits berichteten großen Datenmenge, gab es zu diesem Zeitpunkt nur 7 [110][111][112][113][114][115][116] bzw. 12 [117][118][119][120][121][122][123][124][125][126][127][128] randomisierte Studien, in denen ein Vergleich zwischen dem Dresden-Protokoll und einer unbehandelten Kontrollgruppe bzw. anderen Protokollen durchgeführt wurde.…”