Prevalence of Corneal Astigmatism in Patients before Cataract Surgery in Northern China

Table 1

Patient demographics compared with 5 other published studies.

	Present	Guan et al. [12]	Chen et al. [8]	Ferrer-Blasco et al. [7]	Khan and Muhtaseb [5]	De Bernardo; et al. [14]
Eyes/patients	12449/6908	1430/827	4831/2849	4540/2415	1230/746	757/380
Age (y)
Mean ± SD	69.80 ± 11.15	72.27 ± 11.59	70.56 ± 9.55	60.59 ± 9.87	75.54 ± 0.71	71.89 ± 10.19
Range	30, 97	16, 98	49, 95	32, 87	30, 104	33, 96
Male/female	3199/3709	359/468	1090/1759	768/1647	343/403	176/204
Corneal astigmatism (D)
Mean ± SD	1.15 ± 0.84	1.07 ± 0.73	1.01 ± 0.69	0.90 ± 0.93	1.03 ± 0.73	1.02 ± 0.69
Range	0.0, 6.63	0.06, 5.52	0.05, 6.59	0.25, 6.75	0.0, 6.2	0.06, 4.57
K1 mean ± SD	43.93 ± 1.67	43.57 ± 1.56	43.76 ± 1.53	43.48 ± 1.61	43.43 ± 1.49	43.54 ± 1.43
K2 mean ± SD	45.08 ± 1.73	44.64 ± 1.65	44.76 ± 1.56	44.08 ± 1.59	44.46 ± 1.56	44.56 ± 1.52
Corneal astigmatism (%)
≤0.5 D	20.76	21.2*	23.14	58.8	24.47	23.38
≥1.0 D	47.27	45.37	41.3	34.8	40.4	41.74
≥2.0 D	13.16	10.33	8.22	9.26**	9.67	8.32
≥3.0 D	3.75	2.22	3.52	5.61***	4.61	2.64

∗Not including 0.5 D, ∗∗not including 2.0 D, and ∗∗∗not including 3.0 D.
D = diopter, K1 = flat keratometry, and K2 = steep keratometry.