Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada.
Eye Contact Lens. 2021 Feb 1;47(2):127-133. doi: 10.1097/ICL.0000000000000683.
To visualize the deposition of fluorescein isothiocyanate (FITC) lysozyme on daily disposable contact lenses (CLs) using a novel blink model.
Three daily disposable conventional hydrogel CLs (etafilcon A, omafilcon A, and nelfilcon A) and three silicone hydrogel CLs (delefilcon A, senofilcon A, and somofilcon A) were evaluated in the study. The CLs were mounted onto a novel blink model and exposed to an artificial tear solution containing FITC lysozyme for 2 and 10 hr. The flow rate and blink speed were set to 1 μL/min and 6 blinks/min, respectively. After the incubation period, a 5-mm-diameter disc was punched out from the center of the lens and mounted on a microscope slide. The slides were imaged using the Zeiss 510 Meta confocal laser scanning microscope, which scanned the lens from the front to the back surface at 5-μm increments.
There was an increase in deposition of FITC lysozyme for all lens types with increasing incubation time (P<0.05), with the exception of somofilcon A, which did not show statistical significance between 2 and 10 hr (P>0.05). The conventional hydrogel CLs deposited higher amounts of FITC lysozyme than the silicone hydrogel CLs (P<0.001), with etafilcon A depositing the highest at all time points (P<0.05). Interestingly, at the 2-hr incubation time, most CLs showed a higher amount of deposition at the front surface than the back surface of the lens. In particular, etafilcon A showed preferred deposition at the front surface at all time points.
The results suggest that there is differential deposition at the front surface of the CL, which is exposed to the prelens tear film, compared with the back surface of the CL, which is exposed to the postlens tear film. Therefore, it may be beneficial to design CL materials with differing surface properties for the front and back surfaces of the CL to enhance interactions with the tear film and ocular surface.
使用新型眨眼模型可视化荧光素异硫氰酸酯（FITC）溶菌酶在日戴型隐形眼镜（CL）上的沉积。
本研究评估了三种日戴型传统水凝胶 CL（etafilcon A、 omafilcon A 和 nelfilcon A）和三种硅水凝胶 CL（delefilcon A、 senofilcon A 和 somofilcon A）。将 CL 安装在新型眨眼模型上，然后将其暴露于含有 FITC 溶菌酶的人工泪液中 2 和 10 小时。将流速和眨眼速度分别设置为 1 μL/min 和 6 次/分钟。孵育期结束后，从镜片中心冲出一个 5mm 直径的圆盘，并安装在显微镜载玻片上。使用 Zeiss 510 Meta 共聚焦激光扫描显微镜对载玻片进行成像，该显微镜以 5μm 的增量从前表面扫描到后表面。
随着孵育时间的增加（P<0.05），所有类型的镜片都增加了 FITC 溶菌酶的沉积，除了 somofilcon A，其在 2 和 10 小时之间没有统计学意义（P>0.05）。与硅水凝胶 CL 相比，传统水凝胶 CL 沉积了更多的 FITC 溶菌酶（P<0.001），其中 etafilcon A 在所有时间点沉积量最高（P<0.05）。有趣的是，在 2 小时孵育时间，大多数 CL 在前表面的沉积量高于镜片后表面。特别是，etafilcon A 在所有时间点都在前表面优先沉积。
结果表明，CL 的前表面（暴露于预泪膜）与 CL 的后表面（暴露于后泪膜）相比，存在差异沉积。因此，为 CL 的前表面和后表面设计具有不同表面特性的 CL 材料以增强与泪膜和眼表面的相互作用可能是有益的。
