Yu Qing, Wu Jiang-Xiu, Zhang He-Ning, Ye Sheng, Dong Shi-Qi, Zhang Chen-Hao
New Vision Eye Clinic, Shanghai 200011, China.
Int J Ophthalmol. 2013 Apr 18;6(2):178-82. doi: 10.3980/j.issn.2222-3959.2013.02.14. Print 2013.
To record aberrations with a corneal topographic device on the anterior surface of the cornea at different time-points prior to wearing and following discontinued use of rigid gas permeable (RGP) contact lenses. The effect of wearing RGP on the anterior surface of the cornea was discussed to provide guidance for clinical refractive error correction.
The study objects were 24 eyes from 24 patients. All patients underwent identical examination procedures prior to lens use, as well as afterwards, including slit-lamp examination, non-contact tonometer measurement, computer optometry and corneal curvature measurement, subjective refraction test, and corneal topography analysis. The patients wore contact lenses everyday for 1 month and then discontinued. Corneal topographies were recorded at certain time points of 30 minutes, 1 day, 3, 7 and 14 days following use.
Total corneal aberration at each time point following discontinued use of RGP contact lenses was less than the time point prior to use. Detailed results were as follows: root mean square (RMS) (pre)=(1.438±0.328)µm, RMS (30 minutes)=(1.076±0.355)µm, RMS (1 day)=(1.362±0.402)µm, RMS (3 days)=(1.373±0.398)µm, RMS (7 days)=(1.387±0.415)µm, and RMS (14 days)=(1.430±0.423)µm. Results showed that at 30 minutes after discontinued use of RGP contact lenses, almost all 2(nd)- and 3(rd)-order aberrations change. Quadrafoil Z10 and spherical Z12 of the 4(th)-order were also changed. Alterations to Z5, Z6, and Z12 at 1 day after discontinued use were significant differences compared with the time period prior to RGP use: Z5 and Z6 decreased, and Z12 increased slightly. Z5 and Z6 remained decreased at 3 days after discontinued use, but Z9 and Z10 continued to increase and Z12 returned to levels prior to RGP use. At 14 days after discontinued use, all aberrations were not significantly different from the values prior to use.
The use RGP contact lenses greatly reduced total aberration of the anterior surface of the cornea. Changes to 2(nd)- and 3(rd)-order aberrations (including Z3, Z4, Z5, Z6, Z7, and Z8) were more significant. Following discontinued use of RGP contact lenses, the majority of lower order aberrations returned to original levels in a short period of time. During this process, a transient higher order aberration appeared, but all changes disappeared within 14 days after discontinued use of RGP contact lenses.
使用角膜地形图仪记录硬性透气性（RGP）隐形眼镜佩戴前及停戴后不同时间点角膜前表面的像差。探讨佩戴RGP对角膜前表面的影响，为临床屈光不正矫正提供指导。
研究对象为24例患者的24只眼。所有患者在戴镜前及戴镜后均接受相同的检查程序，包括裂隙灯检查、非接触眼压测量、电脑验光及角膜曲率测量、主观验光测试和角膜地形图分析。患者每天佩戴隐形眼镜1个月，然后停戴。在停戴后的30分钟、1天、3天、7天和14天的特定时间点记录角膜地形图。
停戴RGP隐形眼镜后各时间点的总角膜像差均小于戴镜前的时间点。详细结果如下：均方根（RMS）（戴镜前）=（1.438±0.328）µm，RMS（30分钟）=（1.076±0.355）µm，RMS（1天）=（1.362±0.402）µm，RMS（3天）=（1.373±0.398）µm，RMS（7天）=（1.387±0.415）µm，RMS（14天）=（1.430±0.423）µm。结果显示，停戴RGP隐形眼镜30分钟后，几乎所有二阶和三阶像差均发生变化。四叶草Z10和四阶球面Z12也发生了变化。停戴1天后Z5、Z6和Z12的变化与戴RGP前相比有显著差异：Z5和Z6降低，Z12略有升高。停戴3天后Z5和Z6仍降低，但Z9和Z10继续升高，Z12恢复到戴RGP前的水平。停戴14天后，所有像差与戴镜前的值无显著差异。
佩戴RGP隐形眼镜可显著降低角膜前表面的总像差。二阶和三阶像差（包括Z3、Z4、Z5、Z6、Z7和Z8）的变化更为显著。停戴RGP隐形眼镜后，大多数低阶像差在短时间内恢复到原来的水平。在此过程中，出现了短暂的高阶像差，但在停戴RGP隐形眼镜14天内所有变化均消失。
