Various cross-linking methods inhibit the collagenase I degradation of rabbit scleral tissue.

BACKGROUND: Collagen cross-linking of the sclera is a promising approach to strengthen scleral rigidity and thus to inhibit eye growth in progressive myopia. Additionally, cross-linking might inhibit degrading processes in idiopathic melting or in ocular inflammatory diseases of the sclera. Different cross-linking treatments were tested to increase resistance to enzymatic degradation of the rabbit sclera. METHODS: Scleral patches from rabbit eyes were cross-linked using paraformaldehyde, glutaraldehyde or riboflavin combined with UV-A-light or with blue light. The patches were incubated with collagenase I (MMP1) for various durations up to 24 h to elucidate differences in scleral resistance to enzymatic degradation. Degraded protein components in the supernatant were detected and quantified using measurements of Fluoraldehyde o-Phthaldialdehyde (OPA) fluorescence. RESULTS: All cross-linking methods reduced the enzymatic degradation of rabbit scleral tissue by MMP1. Incubation with glutaraldehyde (1%) and paraformaldehyde (4%) caused nearly a complete inhibition of enzymatic degradation (down to 7% ± 2.8 of digested protein compared to control). Cross-linking with riboflavin/UV-A-light reduced the degradation by MMP1 to 62% ± 12.7 after 24 h. Cross-linking with riboflavin/blue light reduced the degradation by MMP1 to 77% ± 13.5 after 24 h. No significant differences could be detected comparing different light intensities, light exposure times or riboflavin concentrations. CONCLUSIONS: The application of all cross-linking methods increased the resistance of rabbit scleral tissue to MMP1-degradation. Especially, gentle cross-linking with riboflavin and UV-A or blue light might be a clinical approach in future.

Shorter hospital stays in epistaxis patients with atrial fibrillation when taking rivaroxaban or apixaban versus phenprocoumon.

Patients taking oral anticoagulants (OACs) currently represent one-third of all patients treated for epistaxis and an upward trend is expected. New direct oral anticoagulants (DOACs) have been on the market for approximately 10 years. DOACs are favoured over Vitamin K-Antagonists (VKAs) in the current guidelines. There are barely studies that investigate the impact of DOACs on patients with epistaxis. A retrospective study was performed analysing all patients who had stationary treatment for epistaxis from 01.01.2011 to 01.01.2018 in a tertiary care centre. In a total of 466 patients, 46.1% were on OACs. The main indication was atrial fibrillation (AF, 67.4%).The number of DOACs taken surpassed that of the VKAs during the past 2 years. The length of hospital stay was significantly longer in the phenprocoumon group (3 ± 0.2 days) in comparison to both the rivaroxaban (2.3 ± 0.1) and the apixaban (2.2 ± 0.1) groups (p = 0.005). Posterior epistaxis occurred more frequently in the phenprocoumon group (10.8%) than in the rivaroxaban (0%) and apixaban (0%) groups (p = 0.03). A correlation between CHA2DS2-VASc score (risk score for apoplexy in patients with AF, p = 0.01), HAS-BLED score (score for assessment of major bleeding in patients taking anticoagulants with AF, p = 0.006), and length of hospital stay (p = 0.002) with recurrence of epistaxis was found. Shorter hospital stays and exclusively anterior bleeding was noted in AF patients taking rivaroxaban and apixaban, whereas AF patients taking phenprocoumon stayed in hospital longer and had more posterior bleeding.