Table 7.
Prevalence of astigmatism (better eye cylinder power ≥1.50 diopters), overall and by subtypes of astigmatism, stratified by age, in African American and Hispanic children in the Multi-Ethnic Pediatric Eye Disease Study.
| Age group in months |
N | Prevalence of astigmatism ≥1.50 D n (%)* |
Pre valence of subtypes of astigmatism ≥1.50 D n (%)* |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| WTR | ATR | OBL | ||||||||
| AA | Hisp | AA | Hisp | AA | Hisp | AA | Hisp | AA | Hisp | |
| 6 to 11 | 277 | 296 | 34 (12.3) | 70 (23.7) | 26 (9.4) | 63 (21.4) | 4 (1.4) | 0 (0.0) | 4 (1.4) | 7 (2.4) |
| 12 to 23 | 549 | 543 | 31 (5.7) | 49 (9.0) | 14 (2.6) | 44 (8.1) | 9 (1.6) | 1 (0.2) | 8 (1.5) | 4 (0.7) |
| 24 to 35 | 545 | 572 | 34 (6.3) | 41 (7.2) | 27 (5.0) | 34 (6.0) | 7 (1.3) | 2 (0.4) | 0 (0.0) | 5 (0.9) |
| 36 to 47 | 532 | 532 | 19 (3.6) | 38 (7.2) | 14 (2.6) | 37 (0.7) | 4 (0.8) | 0 (0.0) | 1 (0.2) | 1 (0.2) |
| 48 to 59 | 548 | 543 | 25 (4.6) | 41 (7.2) | 20 (3.7) | 039 (7.2) | 0 (0.0) | 0 (0.0) | 5 (0.9) | 2 (0.4) |
| 60 to 72 | 543 | 544 | 28 (5.2) | 44 (8.1) | 23 (4.2) | 42 (7.7) | 1 (0.2) | 0 (0.0) | 4 (0.7) | 2 (0.4) |
| Total | 2994 | 3030 | 171 (5.7) | 283 (9.4) | 124 (4.1) |
259 (8.6) | 25 (0.8) | 3 (0.1) | 22 (0.7) | 21 (0.7) |
AA: African American; Hisp: Hispanic; D: diopters
Percentage of total in corresponding age and ethnic group
WTR: With-the-rule astigmatism, defined as astigmatism with the axis of greatest power within +/− 15 degrees of 90, i.e., in the range [75–105°]; ATR: Against-the-rule astigmatism, defined as astigmatism with the axis of greatest power within +/− 15 degrees of 180, i.e., in the range [1–15°] or [165–180°]; OBL: Oblique axis astigmatism, which includes all other orientations (axis of greatest power in the range [106–164°] or [16–74°]).
The better eye is defined as the eye with the least absolute amount of cylindrical refractive error.
In ties for magnitude, WTR astigmatism is considered better than ATR astigmatism. WTR and ATR are considered better than oblique. There were no ties for magnitude between ATR and WTR astigmatism ≥1.50 D.