Table 8.

Prevalence of astigmatism in the worse eye for African-American Children in the Baltimore Pediatric Eye Disease Study and the Multi-Ethnic Pediatric Eye Disease Study.

Age group in months	Prevalence of astigmatism ≥1.50D n (%)*		Prevalence of astigmatism ≥3.00D n (%)*		Prevalence of subtypes of astigmatism ≥50 D n (%)*
					WTR		ATR		OBL
	M	B	M	B	M	B	M	B	M	B
6 to 11 months (M, n=277 B, n=83)	70 (25.3)	13 (16.0)	6 (2.2)	0 (0.0)	36 (13.0)	6 (7.4)	15 (5.4)	3 (3.7)	19 (6.9)	4 (4.9)
12 to 23 months (M, n=549 B, n=181)	75 (13.7)	20 (10.8)	6 (1.1)	0 (0.0)	33 (6.0)	12 (6.5)	20 (3.6)	3 (1.6)	22 (4.0)	5 (2.7)
24 to 35 months (M, n=545 B, n=248)	75 (13.8)	34 (13.8)	3 (0.6)	3 (1.2)	42 (7.7)	18 (7.3)	19 (3.5)	2 (0.8)	14 (2.6)	14 (5.7)
36 to 47 months (M, n=532 B, n=240)	36 (6.8)	33 (13.9)	4 (0.8)	2 (0.8)	25 (4.7)	27 (11.4)	5 (0.9)	1 (0.4)	6 (1.1)	5 (2.1)
48 to 59 months (M, n=548 B, n=261)	64 (11.7)	31 (12.0)	7 (1.3)	5 (1.9)	46 (8.4)	26 (10.1)	6 (1.1)	0 (0.0)	12 (2.2)	5 (1.9)
60 to 72 months (M, n=543 B, n=245)	59 (10.9)	32 (13.2)	11 (2.0)	9 (3.7)	50 (9.2)	23 (9.5)	2 (0.4)	3 (1.2)	7 (1.3)	6 (2.5)
Total (M, n=2994 B, n=1268)	379 (12.7)	163 (13.0)	37 (1.2)	19 (1.5)	232 (7.7)	112 (9.0)	67 (2.2)	12 (1.0)	80 (2.7)	39 (3.1)

AA: African American; Hisp: Hispanic; D: diopters

^*Percentage of total in corresponding age and study 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 worse eye is defined as the eye with the largest absolute amount of cylindrical refractive error.

M: MEPEDS (Multi-Ethnic Pediatric Eye Disease Study); B: BPEDS (Baltimore Pediatric Eye Disease Study).