Romero-Jiménez Miguel, Santodomingo-Rubido Jacinto, González-Meijóme Jose-Manuel, Flores-Rodriguez Patricia, Villa-Collar Cesar
MRG Doctores S.C, Madrid, Spain.
Menicon R&DIC, Menicon Co., Ltd, Japan.
Cont Lens Anterior Eye. 2015 Feb;38(1):48-53. doi: 10.1016/j.clae.2014.09.012. Epub 2014 Oct 23.
To evaluate how soft lens power affects rigid gas-permeable (RGP) lens power and visual acuity (VA) in piggyback fittings for keratoconus.
Sixteen keratoconus subjects (30 eyes) were included in the study. Piggyback contact lens fittings combining Senofilcon-A soft lenses of -6.00, -3.00, +3.00 and +6.00 D with Rose K2 RGP contact lenses were performed. Corneal topography was taken on the naked eye and over each soft contact lens before fitting RGP lenses. Mean central keratometry, over-refraction, RGP back optic zone radius (BOZR) and estimated final power as well as VA were recorded and analyzed.
In comparison to the naked eye, the mean central keratometry flattened with both negative lens powers (p<0.05 in all cases), did not change with the +3.00 soft lens power (p=1.0); and steepened with the +6.00 soft lens power (p=0.02). Rigid gas-permeable over-refraction did not change significantly between different soft lens powers (all p>0.05). RGP's BOZR decreased significantly with both positive in comparison with both negative soft lens powers (all p<0.001), but no significant differences were found among negative- or positive-powers separately (both p>0.05). Estimated RGP's final power increased significantly with positive in comparison with negative lens powers (all p<0.001), but no significant differences were found among negative or positive lens powers separately (both p>0.05). Visual acuity did not change significantly between the different soft lens powers assessed (all p>0.05).
The use of negative-powered soft lenses in piggyback fitting reduces RGP lens power without impacting VA in keratoconus subjects.
评估在圆锥角膜的背驮式配镜中，软性镜片度数如何影响硬性透气性（RGP）镜片度数和视力（VA）。
16名圆锥角膜受试者（30只眼）纳入本研究。进行了Senofilcon - A -6.00D、-3.00D、+3.00D和+6.00D软性镜片与Rose K2 RGP隐形眼镜的背驮式隐形眼镜配镜。在佩戴RGP镜片之前，对裸眼以及每片软性隐形眼镜进行角膜地形图检查。记录并分析平均中央角膜曲率、复验光度、RGP后光学区半径（BOZR）和估计的最终度数以及视力。
与裸眼相比，两种负度数软性镜片均使平均中央角膜曲率变平（所有情况p<0.05），+3.00D软性镜片度数时未改变（p = 1.0）；而+6.00D软性镜片度数时变陡（p = 0.02）。不同软性镜片度数之间，硬性透气性复验光度无显著变化（所有p>0.05）。与两种负度数软性镜片相比，两种正度数软性镜片的RGP的BOZR均显著降低（所有p<0.001），但负度数或正度数之间分别比较无显著差异（均p>0.05）。与负度数软性镜片相比，正度数软性镜片的估计RGP最终度数显著增加（所有p<0.001），但负度数或正度数之间分别比较无显著差异（均p>0.05）。在评估的不同软性镜片度数之间，视力无显著变化（所有p>0.05）。
在圆锥角膜受试者的背驮式配镜中使用负度数软性镜片可降低RGP镜片度数，而不影响视力。
