Purpose

To evaluate the changes in corneal epithelial thickness and corneal anterior and posterior curvatures during the day, and the effect of wearing daily disposable soft contact lenses.

Methods

Thirty-two healthy volunteers were enrolled in a randomized crossover study. At the baseline visit, corneal and epithelial thickness maps (OCT; Optovue, Inc., Fremont, CA, USA) and keratometric measurements (Pentacam, Oculus, GmbH, Germany) were performed in the morning and in the afternoon (8 hours after). Then, each subject was fitted with the following brands of daily disposable contact lenses in random order: Dailies Total 1 (Delefilcon A), Dailies Aqua Comfort (Nelfilcon A), TruEye (Narafilcon A) and Biotrue Oneday (Nesofilcon A) on different days. All fitted lenses had a power of −3.00 diopters (D). Measurements were repeated before putting the contact lens on and after an-eight-hour contact lens wear.

Results

With no lens wear, the anterior topographic indices showed significant steepening [Kflat: p < 0.0001; Ksteep: p < 0.0001 and maximum keratometry value (Kmax): p = 0.04] and the corneal thickness significantly decreased in the central and temporal portion of the cornea in the afternoon. There were no significant changes in the posterior topographical indices and corneal epithelial thickness. With contact lens wear, no significant change occurred in the corneal and epithelial thickness, and the anterior and posterior curvatures during the day (all p values >0.05). There was no statistically significant difference in the epithelial thickness among the groups wearing different contact lens types (p > 0.05).

Conclusions

Anterior corneal topographic indices steepen depending on the natural diurnal variations. Daily wear of soft contact lenses appears to mask this steepening. The corneal epithelial thickness is not affected by daily disposable soft contact lenses.

中文翻译：

---

角膜上皮厚度和角膜曲率在白天的变化：日抛隐形眼镜佩戴的影响。

目的

评价白天角膜上皮厚度和角膜前后曲率的变化，以及配戴日抛型软性隐形眼镜的效果。

方法

三十二名健康志愿者参加了一项随机交叉研究。在基线访问时，上午和下午（8 小时后）进行角膜和上皮厚度图（OCT；Optovue, Inc., Fremont, CA, USA）和角膜曲率测量（Pentacam，Oculus，GmbH，德国） . 然后，每个受试者在不同的日子里随机配戴以下品牌的日抛型隐形眼镜：Dailies Total 1 (Delefilcon A)、Dailies Aqua Comfort (Nelfilcon A)、TruEye (Narafilcon A) 和 Biotrue Oneday (Nesofilcon A) . 所有安装的镜片都具有 -3.00 屈光度 (D)。在戴上隐形眼镜之前和佩戴隐形眼镜八小时之后重复测量。

结果

在没有佩戴镜片的情况下，前部地形指数显示出显着的陡峭 [Kflat：p < 0.0001；Ksteep：p < 0.0001，最大角膜曲率值（Kmax）：p = 0.04]，下午角膜中央和颞部的角膜厚度显着降低。后部地形指数和角膜上皮厚度没有显着变化。戴隐形眼镜后，角膜和上皮厚度以及白天的前后曲率没有发生显着变化（所有 p 值 > 0.05）。佩戴不同类型隐形眼镜的组间上皮厚度差异无统计学意义（p > 0.05）。

结论

前角膜地形指数根据自然昼夜变化而变陡。每天佩戴软性隐形眼镜似乎掩盖了这种陡峭。角膜上皮厚度不受日抛软性隐形眼镜的影响。