Abstract:
Changes in the biomechanical and biochemical properties of the human cornea play an important role in the pathogenesis of ectatic diseases. A number of conditions in primarily acquired (keratoconus or pellucid marginal degeneration) or secondarily induced (iatrogenic keratectasia after refractive laser surgeries) ectatic disorders lead to decreased biomechanical stability. Corneal collagen cross-linking (CXL) represents a technique to slow or even halt the progression of ectatic pathologies. In this procedure, riboflavin is applied in combination with ultraviolet A radiation. This interaction induces the production of reactive oxygen species, which leads to the formation of additional covalent bonds between collagen molecules and subsequent biomechanical corneal strengthening. This procedure is so far the only method that partially interferes etiopathogenetically in the treatment of ectatic diseases that slows or stops the process of corneal destabilization, otherwise leading to the need for corneal transplantation. Besides, CXL process increases markedly resistance of collagenous matrix against digesting enzymes supporting its use in the treatment of corneal ulcers. Since the discovery of this therapeutic procedure and the first laboratory experiments, which confirmed the validity of this method, and the first clinical studies that proved the effectiveness and safety of the technique, it has been spread and adopted worldwide, even with further modifications. Making use of the Bunsen-Roscoe photochemical law it was possible to shorten the duration of this procedure in accelerated CXL and thus improve the clinical workflow and patient compliance while maintaining the efficacy and safety of the procedure. The indication spectrum of CXL can be further expanded by combining it with other vision-enhancing procedures such as individualized topographically-guided excimer ablation. Complementing both techniques will allow a patient with a biomechanically stable cornea to regularize it and improve visual acuity without the need for tissue transplantation, leading to a long-term improvement in quality of life.
摘要:
人角膜的生物力学和生化特性的变化在扩张疾病的发病机理中起着重要作用。主要是获得性(圆锥角膜或透明边缘变性)或继发性(屈光性激光手术后医源性角膜扩张症)的许多疾病导致生物力学稳定性降低。角膜胶原交联(CXL)代表了减缓或甚至停止外生性病变进展的技术。在这个过程中,核黄素与紫外线A辐射结合使用。这种相互作用诱导了活性氧的产生,这导致胶原蛋白分子之间形成额外的共价键和随后的生物力学角膜强化。到目前为止,该程序是唯一的方法,在部分病因上干扰的方法,可以减缓或停止角膜失稳的过程,否则导致需要角膜移植。此外,CXL过程显着增加胶原基质对消化酶的抗性,支持其用于治疗角膜溃疡。自从发现这种治疗方法和第一次实验室实验以来,这证实了该方法的有效性,以及第一个证明该技术有效性和安全性的临床研究,它已经在世界范围内传播和采用,即使有进一步的修改。利用Bunsen-Roscoe光化学定律,可以在加速CXL中缩短此程序的持续时间,从而改善临床工作流程和患者依从性,同时保持程序的有效性和安全性。CXL的指示光谱可以通过将其与其他视觉增强程序(例如个性化的地形引导准分子消融)组合来进一步扩展。这两种技术的补充将允许具有生物力学稳定角膜的患者在不需要组织移植的情况下对其进行调节并提高视力。导致生活质量的长期改善。