Table 2.
Spherical Equivalent and Myopia Prevalence in Children From Different Age Blocks at the Four Study Visits
| Spherical Equivalent (D) | Myopia Prevalence (%) | |||||||
|---|---|---|---|---|---|---|---|---|
| Visit | Block 1 | Block 2 | Block 3 | P | Block 1 | Block 2 | Block 3 | P |
| Grade 1 | 1.30 ± 0.67 | 1.31 ± 0.73 | 1.32 ± 0.64 | 0.971 | — | — | — | |
| Grade 2 | 0.96 ± 0.92 | 1.06 ± 0.88 | 0.98 ± 0.86 | 0.558 | 12/184 (6.52) | 11/172 (6.40) | 12/180 (6.67) | 0.995 |
| Grade 3 | 0.48 ± 1.20 | 0.51 ± 1.09 | 0.52 ± 1.08 | 0.926 | 27/178(15.17) | 28/163 (17.18) | 26/180 (14.44) | 0.772 |
| Grade 4 | −0.30 ± 1.62 | −0.33 ± 1.53 | −0.20 ± 1.42 | 0.663 | 86/212(40.57) | 81/194(41.75) | 77/204(37.75) | 0.702 |
Block 1: born May to August 2003; Block 2: born January to April 2003; and Block 3: born September to December 2002.