Skip to main content

Table 1 Characteristics of study participants (N = 4801)

From: Astigmatism in school students of eastern China: prevalence, type, severity and associated risk factors

Participant characteristics

 

Age (years)

n (%)

 5

1 (0.02%)

 6

292 (6.1%)

 7

345 (7.2%)

 8

359 (7.5%)

 9

369 (7.7%)

 10

360 (7.5%)

 11

385 (8.0%)

 12

353 (7.3%)

 13

374 (7.8%)

 14

365 (7.6%)

 15

371 (7.7%)

 16

361 (7.5%)

 17

370 (7.7%)

 18

370 (7.7%)

 19

121 (2.5%)

 20

5 (0.1%)

 Mean (SD)

12.3 (3.8)

Gender

 Male

2647 (55.1%)

 Female

2154 (44.9%)

Grade

 Kindergarten

381 (7.9%)

 Grade 1

331 (6.9%)

 Grade 2

366 (7.6%)

 Grade 3

371 (7.7%)

 Grade 4

367 (7.6%)

 Grade 5

376 (7.8%)

 Grade 6

368 (7.7%)

 Grade 7

376 (7.8%)

 Grade 8

360 (7.5%)

 Grade 9

346 (7.2%)

 Grade 10

383 (8.0%)

 Grade 11

373 (7.8%)

 Grade 12

403 (8.4%)

School location

 Urban

2691 (56.1%)

 Rural

2110 (43.9%)

Spherical equivalent of more astigmatic eye (Diopters)

  ≤ −6

351 (7.3%)

  > −6, ≤ −5

267 (5.6%)

  > −5, ≤ −4

414 (8.6%)

  > −4, ≤ −3

510 (10.6%)

  > −3, ≤ −2

584 (12.2%)

  > −2, ≤ −1

768 (16.0%)

  > −1, ≤ −0.5

557 (11.6%)

  > −0.5, < 0.5

1076 (22.4%)

  ≥ 0.5, < 1.0

171 (3.6%)

  ≥ 1.0

103 (2.2%)

Cylinder of more astigmatic eye (diopters)

 0

204 (4.3%)

  > 0, < 0.5

952 (19.8%)

  ≥ 0.5, < 1.0

2063 (43.0%)

  ≥ 1.0, < 1.5

902 (18.8%)

  ≥ 1.5, < 2.0

349 (7.3%)

  ≥ 2.0, < 2.5

162 (3.4%)

  ≥ 2.5, < 3.0

66 (1.4%)

  ≥ 3.0, < 4.0

73 (1.5%)

  ≥ 4.0

30 (0.6%)

 Mean (SD)

0.87 (0.75)

 Median (1st quartile, 3rd quartile)

0.75 (0.50, 1.12)

 Minimum, Maximum

0, 15

Astigmatism ≥ 1.5 diopters

680 (14.2%)

 With-the-rule

575 (84.6%)

 Against-the-rule

11 (1.62%)

 Oblique

94 (13.8%)

Astigmatism ≥ 3.0 diopters

103 (2.15%)

 With-the-rule

93 (90.3%)

 Against-the-rule

2 (1.94%)

 Oblique

8 (7.77%)

  1. SD Standard deviation