Division of Ophthalmic, Neurological and Ear, Nose and Throat Devices, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, United States Food and Drug Administration, Silver Spring, MD, USA.
Eye Contact Lens. 2012 Nov;38(6):350-7. doi: 10.1097/ICL.0b013e318272c470.
To assess material properties that affect preservative uptake by silicone hydrogel lenses.
We evaluated the water content (using differential scanning calorimetry), effective pore size (using probe penetration), and preservative uptake (using high-performance liquid chromatography with spectrophotometric detection) of silicone and conventional hydrogel soft contact lenses.
Lenses grouped similarly based on freezable water content as they did based on total water content. Evaluation of the effective pore size highlighted potential differences between the surface-treated and non-surface-treated materials. The water content of the lens materials and ionic charge are associated with the degree of preservative uptake.
The current grouping system for testing contact lens-solution interactions separates all silicone hydrogels from conventional hydrogel contact lenses. However, not all silicone hydrogel lenses interact similarly with the same contact lens solution. Based upon the results of our research, we propose that the same material characteristics used to group conventional hydrogel lenses, water content and ionic charge, can also be used to predict uptake of hydrophilic preservatives for silicone hydrogel lenses. In addition, the hydrophobicity of silicone hydrogel contact lenses, although not investigated here, is a unique contact lens material property that should be evaluated for the uptake of relatively hydrophobic preservatives and tear components.
评估影响硅水凝胶镜片防腐剂吸收的材料特性。
我们评估了硅水凝胶和传统水凝胶软接触镜的含水量（使用差示扫描量热法）、有效孔径（使用探针渗透法）和防腐剂吸收量（使用高效液相色谱法和分光光度检测法）。
根据可冻结水含量对镜片进行分组与根据总含水量进行分组的结果相似。对有效孔径的评估突出了表面处理和非表面处理材料之间可能存在的差异。镜片材料的含水量和离子电荷与防腐剂吸收程度有关。
目前用于测试接触镜-溶液相互作用的分组系统将所有硅水凝胶与传统水凝胶接触镜分开。然而，并非所有硅水凝胶镜片与相同的接触镜溶液都有类似的相互作用。根据我们的研究结果，我们建议可以使用相同的材料特性来对传统水凝胶镜片进行分组，如含水量和离子电荷，也可以用来预测硅水凝胶镜片对亲水性防腐剂的吸收。此外，硅水凝胶接触镜的疏水性（此处未研究）是一种独特的接触镜材料特性，应该评估其对相对疏水性防腐剂和泪液成分的吸收能力。
