Table 4. Corneal characteristics of high myopia by age.
| Age group(year) | ≤50 | 51–60 | >61 | P value | |
|---|---|---|---|---|---|
| n | 27 | 63 | 77 | ||
| Axial length(mm) | Mean±SD | 29.49±2.62 | 29.67±2.51 | 29.17±2.30 | 0.475# |
| Range | 26.08, 33.89 | 26.09, 36.24 | 26.04, 34.15 | ||
| Astig. C (D) | Mean±SD | 1.25±1.06 | 0.93±0.48 | 1.11±0.70 | 0.407## |
| Range | 0.1, 4.2 | 0.1, 2 | 0.1, 3.6 | ||
| Astig. F (D) | Mean±SD | 1.36±1.00 | 0.84±0.47 | 0.99±0.63 | 0.057## |
| Range | 0.3, 4.4 | 0.1, 2.4 | 0.1, 4 | ||
| Astig. B (D) | Mean±SD | -0.40±0.20 | -0.25±0.15 | -0.28±0.17 | 0.001# |
| Range | -0.1, -0.8 | 0, -0.8 | 0, -0.9 | ||
| Diff. (D) | Mean±SD | -0.11±0.38 | 0.094±0.28 | 0.12±0.35 | 0.007# |
| Range | -0.6, 1.5 | -0.7, 0.7 | -0.9, 1.1 | ||
| Astig. type | WTR (C) | 20 | 18 | 28 | 0.001### |
| ATR (C) | 4 | 33 | 33 | ||
| Obl. (C) | 3 | 12 | 16 | ||
| WTR (F) | 22 | 23 | 35 | 0.003### | |
| ATR (F) | 3 | 24 | 27 | ||
| Obl. (F) | 2 | 16 | 15 | ||
| No astig. (B) | 0 | 3 | 2 | 0.621#### | |
| WTR (B) | 0 | 3 | 3 | ||
| ATR (B) | 27 | 52 | 67 | ||
| Obl. (B) | 0 | 5 | 5 |
Astig. = astigmatism value; Diff. = difference, Astig. C–Astig. F; Astig. type = astigmatism type; WTR = with the rule; ATR = against the rule; Obl. = oblique; No astig. = no astigmatism; D = diopters; C = total cornea; F = anterior corneal surface; B = posterior corneal surface; SD = standard deviation.
#one-way ANOVA
##Kruskal–Wallis
###Pearson’s χ2 test
####Fisher’s exact test