新型的持续配戴高DK值的角膜接触镜(英文)

Contact lens update:high DK lenses for continuous wear

目的 :随着镜片材料和制作工艺的高速发展 ,更加安全地过夜配戴角膜接触镜已逐渐成为可能。方法 :对近年来涉及持续配戴高DK值角膜接触镜的一些研究论文进行综述。结果 :新型的高DK值的硅胶和硅氟化物水凝胶镜片与传统的HEMA镜片相比 ,氧传导性高出 6倍 ,这种新材料的镜片能够从根本上避免任何与组织缺氧有关的并发症。另一个明显的差异在于 :新一代的硅胶镜片有更高的系数。而且在生理反应、匹配以及易操作性方面 ,与传统的低DK值镜片也明显不同。另外 ,尽管与组织缺氧相关的并发症不再存在 ,但是由于镜片覆盖在角巩缘 36 0度范围 ,所以潜在的炎症反应以及机械性的损伤仍然不可避免。因此 ,制造者对涉及角膜生理反应的评估和对配适关系重要性的理解是这些新镜片获得成功过夜配戴的关键。结论 :作为眼保健的从业者 ,视光医师必须了解持续配戴镜片的新进展情况、新材料潜在的副反应和配适特性。

Objective:Technological advances in lens material chemistry and manufacturing have now made it possible to offer patients safer modalities for overnight wear of contact lenses.Methods:This article reviews a number of recent studies that have investigated the use of high DK lenses for continuous wear.Results:The new high DK silicone and fluorosiloxane hydrogels offer up to 6 times greater oxygen transmission than conventional HEMA-based lenses,which has virtually eliminated all complications of lens wear related to hypoxia. Another major difference is the higher modulus of the new-generation,silicone-based lenses. As such,both the physiological response and the physical fit and handling characteristics differ from traditional low-Dk lens designs. Additionally,although the complications related to hypoxia are no longer a concern,because the lenses cover the limbus 360 °,the potential for inflammatory and/or mechanical adverse responses still exists. Assessment of the key markers related to the cornea's physiological response and an understanding of the importance of the fitting relationship is critical for achieving success with overnight wear of these new lens designs.Conclusion:As primary eye care providers,optometrists must be aware of new developments in continuous wear contact lenses,as well as potential adverse responses to the new materials and fitting characteristics.