Table 5.
Correlation between Thinnest Location (CT) and Root Mean Square (RMS) Values.
| Variables | Keratoconus | |||||||
|---|---|---|---|---|---|---|---|---|
| Mild | Moderate | Severe | Total | |||||
| r | P | r | P | r | P | r | P | |
| RMS total | -0.53 | <0.0001* | -0.38 | 0.002 * | +0.03 | 0.81 | -0.60 | <0.0001 * |
| RMS coma | -0.55 | <0.0001 * | -0.36 | 0.003 * | +0.09 | 0.51 | -0.55 | <0.0001 * |
| RMS Trefoil | -0.16 | 0.21 | -0.21 | 0.09 | -0.07 | 0.62 | +0.44 | <0.0001 * |
| RMS Astigmatism | +0.13 | 0.32 | -0.07 | 0.60 | -0.22 | 0.11 | -0.25 | 0.001 * |
| RMS Spherical aberration | -0.13 | 0.33 | -0.06 | 0.63 | -0.11 | 0.42 | -0.28 | 0.0002 * |
r: correlation co-efficient; P: p value; SD: Standard Deviation; RMS: Root Mean Square;
*
: p values less than 0.05 is significant.