Table 5.
Prevalence of subtypes of high astigmatism (worse eye cylinder power ≥3.00 diopters) in African-American and Hispanic children, stratified by age, in the Multi-Ethnic Pediatric Eye Disease Study.
| Age group (months) |
N | Types of Astigmatism n (%)* |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| WTR | ATR | OBL | |||||||||
| AA | Hisp | AA | Hisp | p* | AA | Hisp | p** | AA | Hisp | p* | |
| 6 to 11 | 277 | 296 | 3 (1.1) |
15 (5.1) |
0.006 | 1 (0.4) |
0 (0.0) |
0.30 | 2 (0.7) |
1 (0.3) |
0.52 |
| 12 to 23 | 549 | 543 | 5 (0.9) |
8 (1.5) |
0.39 | 0 (0.0) |
1 (0.2) |
0.31 | 1 (0.2) |
1 (0.2) |
0.99 |
| 24 to 35 | 545 | 572 | 3 (0.6) |
10 (1.8) |
0.06 | 0 (0.0) |
0 (0.0) |
- | 0 (0.0) |
0 (0.0) |
- |
| 36 to 47 | 532 | 532 | 4 (0.8) |
18 (3.4) |
0.003 | 0 (0.0) |
0 (0.0) |
- | 0 (0.0) |
0 (0.0) |
- |
| 48 to 59 | 548 | 543 | 6 (1.1) |
15 (2.8) |
0.045 | 0 (0.0) |
0 (0.0) |
- | 1 (0.2) |
1 (0.2) |
0.99 |
| 60 to 72 | 543 | 544 | 10 (1.8) |
21 (3.8) |
0.046 | 0 (0.0) |
0 (0.0) |
- | 1 (0.2) |
1 (0.2) |
0.999 |
| Total | 2994 | 3030 | 31 (1.0) |
87 (2.9) |
<0.001 | 1 (0.03) |
1 (0.03) |
0.99 | 5 (0.2) |
4 (0.1) |
0.99 |
AA: African American; Hisp: Hispanic
Percentage of total in corresponding age and ethnic group
p: p value for comparison of proportions between ethnicities using Chi-square test
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 worse eye is defined as the eye with the largest absolute amount of cylindrical refractive error. In ties for magnitude, oblique astigmatism is considered worse than WTR or ATR astigmatism. There were no ties for magnitude between ATR and WTR astigmatism ≥3.00 D.