Table 2.
Mean absolute cylindrical power, mean J0 vector component of astigmatism, and mean J45 vector component of astigmatism in right and left eyes of African-American and Hispanic children, stratified by age, in the Multi-Ethnic Pediatric Eye Disease Study.
| Age group In months |
N* | Mean (SD) cylindrical power, in diopters | ||||||
|---|---|---|---|---|---|---|---|---|
| Right eye | Left eye | |||||||
| AA | Hisp | AA | Hisp | p value** | AA | Hisp | p value** | |
| 6 to 11 | 277 | 296 | 0.86 (0.69) |
1.13 (0.87) |
<0.001 | 0.85 (0.67) |
1.08 (0.87) |
<0.001 |
| 12 to 23 | 549 | 543 | 0.65 (0.62) |
0.71 (0.69) |
0.13 | 0.66 (0.59) |
0.70 (0.67) |
0.30 |
| 24 to 35 | 545 | 572 | 0.60 (0.56) |
0.60 (0.63) |
0.97 | 0.62 (0.57) |
0.61 (0.67) |
0.80 |
| 36 to 47 | 532 | 532 | 0.48 (0.50) |
0.60 (0.75) |
0.004 | 0.48 (0.52) |
0.58 (0.78) |
0.01 |
| 48 to 59 | 548 | 543 | 0.52 (0.59) |
0.55 (0.71) |
0.37 | 0.51 (0.60) |
0.54 (0.72) |
0.49 |
| 60 to 72 | 543 | 544 | 0.50 (0.69) |
0.59 (0.83) |
0.0498 | 0.49 (0.64) |
0.52 (0.74) |
0.48 |
| Total | 2994 | 3030 | 0.58 (0.61) |
0.66 (0.76) |
<0.001 | 0.58 (0.60) |
0.64 (0.75) |
<0.001 |
|
Age group in months |
N * | Mean (SD) J0 †in diopters | ||||||
| Right eye | Left eye | |||||||
| AA | Hisp | AA | Hisp | p value ** | AA | Hisp | p value ** | |
| 6 to 11 | 277 | 296 | 0.09 (0.47) |
0.45 (0.47) |
<0.001 | 0.08 (0.49) |
0.43 (0.48) |
<0.001 |
| 12 to 23 | 549 | 543 | 0.01 (0.40) |
0.19 (0.42) |
<0.001 | 0.01 (0.39) |
0.17 (0.42) |
<0.001 |
| 24 to 35 | 545 | 572 | 0.05 (0.37) |
0.14 (0.37) |
<0.001 | 0.04 (0.38) |
0.13 (0.40) |
<0.001 |
| 36 to 47 | 532 | 532 | 0.05 (0.30) |
0.20 (0.40) |
<0.001 | 0.05 (0.32) |
0.18 (0.43) |
<0.001 |
| 48 to 59 | 548 | 543 | 0.12 (0.34) |
0.21 (0.37) |
<0.001 | 0.10 (0.34) |
0.18 (0.38) |
<0.001 |
| 60 to 72 | 543 | 544 | 0.13 (0.37) |
0.24 (0.42) |
<0.001 | 0.12 (0.35) |
0.19 (0.39) |
0.004 |
| Total | 2994 | 3030 | 0.08 (0.37) |
0.22 (0.41) |
<0.001 | 0.07 (0.37) |
0.20 (0.42) |
<0.001 |
|
Age group in months |
N * | Mean (SD) J45 ‡in diopters | ||||||
| Right eye | Left eye | |||||||
| AA | Hisp | AA | Hisp | p value ** | AA | Hisp | p value ** | |
| 6 to 11 | 277 | 296 | −0.01 (0.28) |
0.06 (0.28) |
0.02 | 0.01 (0.23) |
0.00 (0.25) |
0.32 |
| 12 to 23 | 549 | 543 | −0.01 | 0.01 | 0.07 | 0.01 | 0.02 | 0.51 |
| (0.21) | (0.19) | (0.21) | (0.17) | |||||
| 24 to 35 | 545 | 572 | −0.03 (0.17) |
−0.00 (0.18) |
0.02 | 0.04 (0.18) |
0.03 (0.15) |
0.28 |
| 36 to 47 | 532 | 532 | −0.04 (0.16) |
0.00 (0.14) |
<0.001 | 0.03 (0.15) |
0.02 (0.14) |
0.30 |
| 48 to 59 | 548 | 543 | −0.02 (0.15) |
0.00 (0.14) |
0.002 | 0.02 (0.17) |
0.02 (0.14 ) |
0.84 |
| 60 to 72 | 543 | 544 | −0.00 (0.17) |
0.03 (0.16) |
<0.001 | 0.01 (0.15) |
0.01 (0.14) |
0.73 |
| Total | 2994 | 3030 | −0.02 (0.18) |
0.01 (0.18) |
<0.001 | 0.02 (0.18) |
0.02 (0.16) |
0.25 |
N: number of children with data for one or both eyes. One African American and 3 Hispanic children had data for right eye only; one African American and 3 Hispanic children had data for left eye only.
p value: p value for comparison of mean values between ethnicities using Student’s t-test.
J0 vector component of cylindrical refractive error, defined as (−C/2)*Cos2α, where α and C are axis and magnitude of cylindrical refractive error.
J45 vector components of cylindrical refractive error, defined as (−C/2)*Sin2α, where α and C are axis and magnitude of cylindrical refractive error.
AA: African American; Hisp: Hispanic, SD: Standard deviation.