Prevalences of RA, CA and IA by gender and different classification with axes
| RA* % (95% CI) | CA % (95% CI) | IA % (95% CI) | |||||||
| WTR | ATR | Oblique | WTR | ATR | Oblique | WTR | ATR | Oblique | |
| ±15° | |||||||||
| Total | 57.8 (55.4 to 60.2) | 7.9 (6.6 to 9.2) | 34.3 (32.0 to 36.6) | 80.8 (78.9 to 82.6) | 1.6 (1.0 to 2.2) | 17.6(15.9 to 19.4) | 1.2 (0.7 to 1.7) | 69.3 (67.1 to 71.4) | 29.5 (27.4 to 31.7) |
| Boys | 56.8 (53.3 to 60.2) | 7.9 (6.1 to 9.8) | 35.3 (32.0 to 38.6) | 80.7 (78.2 to 83.4) | 1.8 (0.9 to 2.7) | 17.4 (14.9 to 19.9) | 1.1 (0.4 to 1.8) | 68.4 (65.3 to 71.5) | 30.5 (27.4 to 33.5) |
| Girls | 58.8 (55.5 to 62.2) | 7.9 (6.0 to 9.7) | 33.3 (30.1 to 36.5) | 80.8 (78.2 to 83.3) | 1.3 (0.6 to 2.1) | 17.9 (15.4 to 20.4) | 1.2 (0.5 to 1.9) | 70.1 (67.1 to 73.1) | 28.7 (25.7 to 31.6) |
| P value† | 0.36 | 0.45 | 0.40 | 0.52 | 0.27 | 0.43 | 0.52 | 0.23 | 0.22 |
| ±20° | |||||||||
| Total | 66.5 (64.2 to 68.8) | 9.6 (8.1 to 11.0) | 23.9 (21.9 to 26.0) | 87.7 (86.1 to 89.2) | 2.1 (1.5 to 2.8) | 10.2 (8.8 to 11.6) | 3.4 (2.5 to 4.2) | 79.3 (77.4 to 81.2) | 17.3 (15.6 to 19.1) |
| Boys | 65.8 (62.5 to 69.1) | 10.2 (8.1 to 12.2) | 24.0 (21.2 to 27.0) | 87.1 (84.9 to 89.3) | 2.4 (1.4 to 3.4) | 10.5 (8.5 to 12.6) | 3.2 (2.0 to 4.3) | 78.0 (75.3 to 80.8) | 18.8 (16.2 to 21.4) |
| Girls | 67.2 (64.0 to 70.4) | 9.0 (7.0 to 11.0) | 23.8 (20.9 to 26.8) | 88.2 (86.1 to 90.3) | 1.9 (1.0 to 2.8) | 9.9 (7.9 to 11.8) | 3.6 (2.4 to 4.8) | 80.5 (78.0 to 83.1) | 15.9 (13.5 to 18.3) |
| P value† | 0.56 | 0.45 | 0.95 | 0.26 | 0.30 | 0.36 | 0.26 | 0.30 | 0.36 |
| ±30° | |||||||||
| Total | 75.9 (73.8 to 78.0) | 12.6 (11.0 to 14.2) | 11.5 (10.0–13.1) | 92.8 (91.6 to 94.0) | 2.7 (2.0 to 3.6) | 4.5 (3.5 to 5.5) | 4.6 (3.6 to 5.5) | 87.9 (86.4 to 89.5) | 7.5 (6.3 to 8.7) |
| Boys | 74.9 (71.9 to 77.8) | 13.1 (10.8 to 15.5) | 12.0 (9.8 to 14.3) | 92.1 (90.3 to 93.9) | 3.4 (2.2 to 4.6) | 4.5 (3.2 to 6.0) | 4.4 (3.1 to 5.8) | 88.1 (86.0 to 90.2) | 7.5 (5.7 to 9.2) |
| Girls | 76.9 (74.0 to 79.8) | 12.1 (9.9 to 14.3) | 11.0 (8.9 to 13.2) | 93.4 (91.8 to 95.1) | 2.1 (1.2 to 3.1) | 4.5 (3.1 to 5.8) | 4.7 (3.3 to 6.0) | 87.8 (85.6 to 89.9) | 7.5 (5.8 to 9.3) |
| P value† | 0.36 | 0.55 | 0.54 | 0.15 | 0.06 | 0.51 | 0.15 | 0.06 | 0.51 |
*A total of 150 students having RA of 0 were not included for analysis.
†Comparison between genders.
ATR, against-the-rule; CA, corneal astigmatism; IA, internal astigmatism; RA, refractive astigmatism; WTR, with-the-rule.