Paul-Flechsig-Institute of Brain Research, Leipzig University, Liebigstraße 19, 04103, Leipzig, Germany.
Fachbereich SciTec, Ernst-Abbe-Hochschule Jena, University of Applied Sciences, Carl-Zeiß-Promenade 2, 07745, Jena, Germany.
BMC Ophthalmol. 2020 Dec 14;20(1):488. doi: 10.1186/s12886-020-01751-z.
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.
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.
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.
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.
巩膜胶原交联是一种有前途的方法，可以增强巩膜刚性，从而抑制进行性近视的眼球生长。此外，交联可能抑制特发性融解或眼炎性疾病巩膜中的降解过程。为了提高兔巩膜对酶降解的抵抗力，测试了不同的交联处理方法。
使用多聚甲醛、戊二醛或核黄素联合 UV-A 光或蓝光交联兔眼巩膜贴片。将贴片与胶原酶 I（MMP1）孵育不同时间，最长达 24 小时，以阐明巩膜对酶降解的抵抗力差异。使用 Fluoraldehyde o-Phthaldialdehyde（OPA）荧光测量法检测和定量上清液中降解的蛋白成分。
所有交联方法均降低了 MMP1 对兔巩膜组织的酶降解作用。用 1%戊二醛和 4%多聚甲醛孵育几乎完全抑制了酶降解（与对照相比，消化蛋白减少至 7%±2.8）。用核黄素/UV-A 光交联 24 小时后，MMP1 的降解率降低至 62%±12.7。用核黄素/蓝光交联 24 小时后，MMP1 的降解率降低至 77%±13.5。不同的光强度、光暴露时间或核黄素浓度之间没有检测到显著差异。
所有交联方法的应用都增加了兔巩膜组织对 MMP1 降解的抵抗力。特别是用核黄素和 UV-A 或蓝光进行温和交联可能是未来的一种临床方法。
