Table 2 Distributions of cylindrical value, spherical value, axial length and spherical equivalent refraction among grade 1 and 7 samples
From: Low prevalence of myopia among school children in rural China
Mean | Median | Standard error | Standard deviation (Diopter) | Skewness | Kurtosis | Inter Quartile Range (Diopter) | Kolmogorov-Smirnov test | |
|---|---|---|---|---|---|---|---|---|
Grade 1 sample | ||||||||
Cylindrical value (D) | −0.27 | − 0.25 | 0.01 | 0.35 | −3.91 | 25.51 | 0.25 | < 0.001 |
Spherical value (D) | 1.01 | 1.00 | 0.01 | 0.71 | −0.17 | 30.87 | 0.50 | < 0.001 |
Axial length (mm) | 22.64 | 22.65 | 0.01 | 0.69 | 0.10 | 0.74 | 0.89 | < 0.001 |
Spherical equivalent (D) | 0.87 | 0.88 | 0.01 | 0.68 | −1.37 | 40.46 | 0.50 | < 0.001 |
Grade 7 sample | ||||||||
Cylindrical value (D) | −0.36 | −0.25 | 0.01 | 0.39 | −5.88 | 66.64 | 0.25 | < 0.001 |
Spherical value (D) | −0.09 | 0.25 | 0.03 | 1.43 | −1.53 | 6.12 | 1.25 | < 0.001 |
Axial length (mm) | 23.59 | 23.51 | 0.02 | 0.90 | 0.52 | 0.80 | 1.12 | < 0.001 |
Spherical equivalent (D) | −0.27 | 0.15 | 0.03 | 1.46 | −1.69 | 6.27 | 1.38 | < 0.001 |