Eurolens Research, Faculty of Life Sciences, The University of Manchester, Manchester, UK.
J Biomed Mater Res B Appl Biomater. 2010 Feb;92(2):361-5. doi: 10.1002/jbm.b.31522.
This study was designed to derive central and peripheral oxygen transmissibility (Dk/t) thresholds for soft contact lenses to avoid hypoxia-induced corneal swelling (increased corneal thickness) during open eye wear. Central and peripheral corneal thicknesses were measured in a masked and randomized fashion for the left eye of each of seven subjects before and after 3 h of afternoon wear of five conventional hydrogel and silicone hydrogel contact lens types offering a range of Dk/t from 2.4 units to 115.3 units. Curve fitting for plots of change in corneal thickness versus central and peripheral Dk/t found threshold values of 19.8 and 32.6 units to avoid corneal swelling during open eye contact lens wear for a typical wearer. Although some conventional hydrogel soft lenses are able to achieve this criterion for either central or peripheral lens areas (depending on lens power), in general, no conventional hydrogel soft lenses meet both the central and peripheral thresholds. Silicone hydrogel contact lenses typically meet both the central and peripheral thresholds and use of these lenses therefore avoids swelling in all regions of the cornea.
本研究旨在为软性隐形眼镜推导中心和周边氧传导率（Dk/t）阈值，以避免在睁眼佩戴期间因缺氧引起的角膜肿胀（角膜厚度增加）。在下午佩戴 3 小时后，对 7 名受试者的左眼进行了掩蔽和随机角膜中央和周边厚度测量，他们分别佩戴了 5 种不同类型的常规水凝胶和硅水凝胶隐形眼镜，这些镜片的 Dk/t 范围从 2.4 单位到 115.3 单位。对角膜厚度随中央和周边 Dk/t 变化的曲线拟合发现，对于典型的佩戴者，避免睁眼佩戴隐形眼镜时角膜肿胀的阈值为 19.8 和 32.6 单位。尽管一些常规水凝胶软性隐形眼镜能够达到中央或周边镜片区域的这一标准（取决于镜片度数），但总体而言，没有一种常规水凝胶软性隐形眼镜能够同时达到中央和周边阈值。硅水凝胶隐形眼镜通常能同时满足中央和周边的阈值，因此使用这些镜片可以避免角膜所有区域的肿胀。
