METHODS: Fourteen habitual soft CL wearers were exposed to controlled low humidity (5% relative humidity [RH]) in an environmental chamber for 90 min on two separate occasions. First, when wearing their habitual spectacles and then, on a separate visit, when wearing silicone hydrogel CLs that were fitted specifically for this purpose. All participants had adapted to the new CL prior to data collection. Three non-invasive objective measurements were taken at each visit: blinking rate, objective ocular scatter (measured using the objective scatter index) and ocular surface cooling rate (measured using a long-wave infrared thermal camera). At each visit, measurements were taken before the exposure in comfortable environmental conditions (RH: 45%), and after exposure to environmental stress (low humidity, RH: 5%).
RESULTS: CL wearers showed increased blinking rate (p < 0.005) and ocular scatter (p = 0.03) but similar cooling rate of the ocular surface (p = 0.08) when compared with spectacle wear in comfortable environmental conditions. The exposure to low humidity increased the blinking rate significantly with both types of corrections (p = 0.01). Interestingly, ocular scatter (p = 0.96) and cooling rate (p = 0.73) were not significantly different before and after exposure to low humidity. There were no significant two-way interactions between correction and exposure in any of the measurements.
CONCLUSIONS: CLs significantly increased the blinking rate, which prevented a quick degradation of the tear film integrity as it was refreshed more regularly. It is hypothesised that the increased blinking rate in CL wearers aids in maintaining ocular scatter quality and cooling rate when exposed to a low-humidity environment. These results highlight the importance of blinking in maintaining tear film stability.
方法:十四个习惯性的软CL穿戴者在环境室中暴露于受控的低湿度(5%相对湿度[RH])90分钟。首先,当他们戴着习惯性的眼镜,然后,在单独的访问中,佩戴专门用于此目的的硅胶水凝胶CL时。所有参与者在数据收集之前都适应了新的CL。每次就诊时进行三项非侵入性客观测量:眨眼率,客观眼散射(使用客观散射指数测量)和眼表冷却速率(使用长波红外热像仪测量)。每次访问,在舒适的环境条件下(RH:45%)暴露之前进行测量,以及暴露于环境压力(低湿度,RH:5%)。
结果:与眼镜佩戴者相比,在舒适的环境条件下,CL佩戴者的眨眼率(p<0.005)和眼部散射(p=0.03)增加,但眼表冷却率相似(p=0.08)。在两种类型的校正下,暴露于低湿度下均显着增加了闪烁率(p=0.01)。有趣的是,眼睛散射(p=0.96)和冷却速率(p=0.73)在暴露于低湿度之前和之后没有显着差异。在任何测量中,校正和暴露之间没有显著的双向相互作用。
结论:CLs显著增加眨眼率,这防止了泪膜完整性的快速降解,因为它被更经常地刷新。假设CL佩戴者的眨眼速率增加有助于在暴露于低湿度环境时保持眼部散射质量和冷却速率。这些结果突出了闪烁在保持泪膜稳定性中的重要性。