Table 1.
Characteristics of the Study Population and a Comparison of Normal, Subclinical Keratoconus, and Keratoconus Eyes
| Group, Mean ± SD | P | |||||
|---|---|---|---|---|---|---|
| Parameter | Ka | Nb | Sc | N vs. K | N vs. S | K vs. S |
| Age (y) | 31.5 ± 8.20 | 36.50 ± 9.50 | 31.80 ± 8.30 | 0.159 | 0.331 | 0.566 |
| Kflat (D) | 45.64 ± 1.20 | 42.96 ± 8.20 | 43.41 ± 1.80 | 0.001* | 0.101 | 0.026 |
| Ksteep (D) | 49.33 ± 3.30 | 43.89 ± 2.70 | 44.83 ± 4.90 | 0.000* | 0.095 | 0.035 |
| Astigmatism (D) | 3.02 ± 2.13 | 0.92 ± 0.56 | 1.01 ± 0.75 | 0.000* | 0.821 | 0.001 |
| TCT (µm) | 459.88 ± 16.44 | 532.44 ± 27.14 | 513.19 ± 77.45 | 0.000* | 0.042* | 0.000 |
| I–S value (D) | 5.12 ± 1.76 | 0.04 ± 0.20 | 0.82 ± 0.88 | 0.000* | 0.005* | 0.002 |
Bolded numbers indicate statistically significant difference (P < 0.05).
a
Keratoconus group included 544 subjects and 1038 eyes.
b
Normal group included 579 subjects and 1108 eyes.
c
Subclinical keratoconus group included 546 subjects and 1072 eyes.