The impact of hydrogel lens settling on the thickness of the tears and contact lens.
The impact of hydrogel lens settling on the thickness of the tears and contact lens.
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DOI：
10.1167/iovs.04-0149
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发表时间：
2004-08
影响因子：
4.4
通讯作者：
J. Nichols;P. King-Smith
中科院分区：
文献类型：
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作者：
J. Nichols;P. King-Smith
目的探讨戴透镜对前透镜泪膜（PLTF）、接触透镜和后透镜泪膜（PoLTF）的影响。方法12名接触透镜配戴者（平均年龄32.7岁; 4名男性）在测试前即刻在双眼中植入etafilcon A水凝胶镜片（屈光度：-2.00 D，基弧：8.3 mm）。先前描述的基于反射光谱振荡的干涉技术被用于测量PLTF、接触透镜和PoLTF的厚度。层的厚度由振荡的频率导出。在透镜插入后1分钟采集光谱，此后每分钟采集一次，持续30分钟。使用最小二乘回归拟合来确定每层厚度与时间之间的关系。结果所有受试者的PLTF厚度的组合数据与指数衰减加上恒定厚度拟合;初始厚度为4.5微米，时间常数为7.1分钟（P < 0.001），最终厚度为2.5微米。接触透镜的表观厚度以0.051微米/分钟的平均速率线性下降（P < 0.001）。PoLTF厚度保持恒定在2.5微米（P = 0.46）。结论对于大多数受试者来说，在佩戴透镜的前30分钟内，PLTF显着变薄。接触透镜的明显变薄可能是由透镜的真实的变薄引起的，但也可能具有来自在30分钟时间段内改善的对中的贡献。在此期间，警察工作队保持相对稳定。
PURPOSE To investigate the effect of contact lens insertion on the thickness on the prelens tear film (PLTF), the contact lens, and the postlens tear film (PoLTF). METHODS Twelve contact lens wearers (mean age, 32.7 years; four males) inserted etafilcon A hydrogel lenses (power: -2.00 D, base curve: 8.3 mm) in both eyes immediately before testing. Previously described interference techniques, based on oscillations in reflectance spectra, were used to measure the thickness of the PLTF, contact lens, and PoLTF. The thickness of the layers is derived from the frequency of the oscillations. Spectra were captured 1 minute after lens insertion and every minute thereafter for 30 minutes. Least squares regression fits were used to determine the relation between thickness of each layer and time. RESULTS The combined data from all subjects for PLTF thickness were fit with an exponential decay plus a constant thickness; the initial thickness was 4.5 micrometers, the time constant was 7.1 minutes (P < 0.001), and final thickness was 2.5 micrometers. The apparent thickness of the contact lens declined linearly at an average rate of 0.051 micrometers/minute (P < 0.001). The PoLTF thickness remained constant at 2.5 micrometers (P = 0.46). CONCLUSIONS For most subjects, the PLTF thinned significantly over the course of the first 30 minutes of lens wear. The apparent thinning of the contact lens may be caused by a real thinning of the lens, but also may have a contribution from improved centration over the 30-minute period. The PoLTF remained relatively stable during this period.