Payor R E, Robirds S R, Zhang X, Schwallie J D
Clinical Studies Department, CIBA Vision Corporation, Atlanta, Georgia 30136, USA.
CLAO J. 1995 Jul;21(3):163-8.
Lens power accuracy is the most frequently cited requirement for reproducible soft toric lens performance. Power accuracy is even more critical with planned replacement soft toric lenses because of the increased rate at which lenses are replaced. However, no reproducible methodology exists for making such an evaluation. We developed a power measurement method from which measurement error was eliminated. Geometric optical calculation was used to calculate the resulting optical error. The relationship between visual acuity loss and optical errors was used to predict the effect on visual acuity. This method was applied to a sample of 457 Focus Toric soft contact lenses. We found that 83.5 +/- 1.7% of the lenses were accurate enough to deliver one line or less of loss in visual acuity. Our estimate of the clinical problem rate associated with power reproducibility was 3.3 +/- 0.9% of lens pairs. If lenses were replaced on a monthly basis, this would amount to one problem pair every 30 months.
镜片屈光度准确性是可重复的软性散光镜片性能中最常被提及的要求。由于镜片更换频率增加，对于计划更换的软性散光镜片而言，屈光度准确性更为关键。然而，目前尚无用于进行此类评估的可重复方法。我们开发了一种消除测量误差的屈光度测量方法。利用几何光学计算来计算由此产生的光学误差。视力损失与光学误差之间的关系被用于预测对视力的影响。该方法应用于457片Focus Toric软性隐形眼镜样本。我们发现，83.5±1.7%的镜片准确性足以使视力损失不超过一行。我们对与屈光度可重复性相关的临床问题发生率的估计为每对镜片3.3±0.9%。如果每月更换镜片，这相当于每30个月出现一对问题镜片。
