Table 3.
t Tests of Study Variables
| KCN | NRL | P | |
|---|---|---|---|
| Cspot-max, diopters (D) | 53.1 ± 6.5 (41.4–74.3) | 44.5 ± 1.57 (39.6–49.0) | < 0.0001 |
| Pach-min, microns (μ) | 467 ± 57 (319–634) | 548 ± 31 (475–621) | < 0.0001 |
| CCSmax, dimensionless | 8.82 ± 1.70 (6.50–15.27) | 7.06 ± 0.43 (5.93–8.41) | < 0.0001 |
| CCSmin, dimensionless | 6.40 ± 0.54 (4.97–7.42) | 6.14 ± 0.43 (5.07–7.42) | 0.0007 |
| CCSdiff, dimensionless | 2.41 ± 1.76 (0.66–9.31) | 0.92 ± 0.28 (0.40–2.66) | < 0.0001 |
| Distance of Cspot-max to Pach-min, mm | 0.79 ± 0.32 (0.02–1.38) | 1.56 ± 0.76 (0.04–3.28) | < 0.0001 |
CCSdiff = difference between maximum and minimum corneal contribution to stress; CCSmax = maximum zone of corneal contribution to stress; CCSmin = minimum zone of corneal contribution to stress; Cspot-max = maximum zone of tangential curvature; D = diopter; KCN = keratoconus; NRL = normal control; Pach-min = minimum zone of thickness. Data expressed as mean ± standard deviation (range).