Table 2. Annual Incidence of Myopia and High Myopia in Primary and Junior High School Cohorts Based on Refraction Without Cycloplegia.
| Perioda | No./Total No. (%) [95% CI] | |
|---|---|---|
| Myopiab | High Myopiab | |
| Primary school | ||
| 1-2 | 307/1607 (19.1) [17.2-21.0] | 2/1825 (0.1) [0.0-0.3] |
| 2-3 | 305/1288 (23.7) [21.4-26.0] | 4/1799 (0.2) [0.0-0.5] |
| 3-4 | 226/879 (25.7) [22.8-28.6] | 8/1770 (0.5) [0.0-0.9] |
| 4-5 | 194/674 (28.8) [25.4-32.2] | 16/1712 (0.9) [0.2-1.7] |
| 5-6 | 140/463 (30.2) [26.0-34.4] | 26/1620 (1.6) [0.5-2.7] |
| Junior high school | ||
| 7-8 | 221/759 (29.1) [25.9-32.3] | 43/2265 (1.9) [0.9-2.9] |
| 8-9 | 123/495 (24.8) [21.0-28.7] | 48/2044 (2.3) [1.0-3.7] |
a
Each row is the period during which the incidence of new myopia is calculated; fields display the number of students who converted from nonmyopic to myopic between the first stated grade and the second stated grade.
b
Myopia defined as spherical equivalent refraction of −0.50 diopters or less. High myopia defined as spherical equivalent refraction of −6.0 diopters or less.