Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
Ophthalmic Physiol Opt. 2014 Jan;34(1):89-93. doi: 10.1111/opo.12098.
The aim of the study was to evaluate the level of agreement between the 'Representative Value' (RV) of refraction obtained from the Shin-Nippon NVision-K 5001 instrument with values calculated from individual measurement readings using standard algebraic methods.
Cycloplegic autorefraction readings for 101 myopic children aged 8-13 years (10.9 ± 1.42 years) were obtained using the Shin-Nippon NVision-K 5001. Ten autorefractor measurements were taken for each eye. The spherical equivalent (SE), sphere (Sph) and cylindrical component (Cyl) power of each eye were calculated, firstly, by averaging the 10 repeated measurements (Mean SE, Mean Sph and Mean Cyl), and secondly, by the vector representation method (Vector SE, Vector Sph and Vector Cyl). These calculated values were then compared with those of RV (RV SE, RV Sph and RV Cyl) provided by the proprietary software of the NVision-K 5001 using one-way analysis of variance (anova). The agreement between the methods was also assessed.
The SE of the subjects ranged from -5.37 to -0.62 D (mean ± SD, = -2.89 ± 1.01 D). The Mean SE was in exact agreement with the Vector SE. There were no significant differences between the RV readings and those calculated using non-vectorial or vectorial methods for any of the refractive powers (SE, p = 0.99; Sph, p = 0.93; Cyl, p = 0.24). The (mean ± SD) differences were: RV SE vs Mean SE (and also RV SE vs Vector SE) -0.01 ± 0.06 D; RV Sph vs Mean Sph, -0.01 ± 0.05 D; RV Sph vs Vector Sph, -0.04 ± 0.06 D; RV Cyl vs Mean Cyl, 0.01 ± 0.07 D; RV Cyl vs Vector Cyl, 0.06 ± 0.09 D. Ninety-eight percent of RV reading differed from their non-vectorial or vectorial counterparts by less than 0.25 D.
The RV values showed good agreement to the results calculated using conventional methods. Although the formula used to calculate RV by the NVision-K 5001 autorefractor is proprietary, our results provide validation for the use of RV measurements in clinical practice and vision science research.
本研究旨在评估从 Shin-Nippon NVision-K 5001 仪器获得的屈光“代表值”（RV）与使用标准代数方法从个体测量读数计算出的值之间的一致性。
使用 Shin-Nippon NVision-K 5001 对 101 名 8-13 岁（10.9±1.42 岁）的近视儿童进行睫状肌麻痹自动验光读数。每只眼进行 10 次自动折射测量。首先，通过平均 10 次重复测量（平均 SE、平均 Sph 和平均 Cyl）计算每只眼的球镜等效（SE）、球镜（Sph）和圆柱分量（Cyl）功率，其次，通过向量表示法（向量 SE、向量 Sph 和向量 Cyl）计算。使用单因素方差分析（anova）比较这些计算值与 NVision-K 5001 专有软件提供的 RV（RV SE、RV Sph 和 RV Cyl）。还评估了方法之间的一致性。
受试者的 SE 范围为-5.37 至-0.62 D（平均值±标准差，=-2.89±1.01 D）。平均 SE 与向量 SE 完全一致。对于任何屈光力（SE、p=0.99；Sph、p=0.93；Cyl、p=0.24），RV 读数与使用非向量或向量方法计算的读数均无显著差异。差异（平均值±标准差）为：RV SE 与平均 SE（以及 RV SE 与向量 SE）为-0.01±0.06 D；RV Sph 与平均 Sph 为-0.01±0.05 D；RV Sph 与向量 Sph 为-0.04±0.06 D；RV Cyl 与平均 Cyl 为 0.01±0.07 D；RV Cyl 与向量 Cyl 为 0.06±0.09 D。98%的 RV 读数与其非向量或向量读数的差异小于 0.25 D。
RV 值与使用常规方法计算的结果具有良好的一致性。尽管 NVision-K 5001 自动折射仪用于计算 RV 的公式是专有的，但我们的结果为 RV 测量在临床实践和视觉科学研究中的应用提供了验证。
