Table 3.
Univariate linear regression of the baseline predictive factors and its significance on the treatment outcomes
| Variable | Changes in K-max (D) | Changes in BCVA (logMAR) | ||||
|---|---|---|---|---|---|---|
| Regression coefficient | 95% CI | P | Regression coefficient | 95% CI | P | |
| History | ||||||
| Age | 0.019 | −0.052-0.092 | 0.58 | 0.004 | −0.001-0.009 | 0.11* |
| Male sex | −0.159 | −0.964-0.645 | 0.69 | −0.040 | −0.104-0.023 | 0.21 |
| Place of birth (city) | 1.1992 | 0.115-2.282 | 0.03* | −0.105 | −0.189-−0.021 | 0.01* |
| Place of residence (city) | 0.294 | −0.791-1.380 | 0.59 | −0.083 | −0.166-0.0006 | 0.052* |
| Atopic constitution (no) | 1.766 | 0.361-3.171 | 0.01* | 0.0126 | −0.101-0.127 | 0.82 |
| Family history (yes) | −0.103 | −1.540-1.332 | 0.88 | −0.029 | −0.133-0.075 | 0.57 |
| Rubbing frequency | 0.574 | −0.051-1.199 | 0.07* | −0.009 | −0.063-0.043 | 0.72 |
| Sleep apnea (no) | −0.377 | −1.673-0.917 | 0.56 | 0.0305 | −0.072-0.133 | 0.55 |
| Blood group | ||||||
| A+ | 0.935 | −0.662-2.533 | 0.17* | −0.020 | −0.142-0.101 | 0.88 |
| A− | 0.967 | −1.566-3.500 | −0.110 | −0.303-0.083 | ||
| B + | −0.594 | −2.608-1.419 | −0.026 | −0.173-0.120 | ||
| B− | 3.329 | 0.041-6.617 | −0.086 | −0.337-0.165 | ||
| O + | 0.738 | −0.849-2.327 | −0.038 | −0.162-0.085 | ||
| O− | Ref | Ref | Ref | Ref | ||
| Biochemical | ||||||
| IL-6 | 0.002 | −0.003-0.009 | 0.40 | 0.0001 | −0.0003-0.0007 | 0.49 |
| TNF-a | −0.001 | −0.005-0.002 | 0.54 | 0.00002 | −0.0003-0.0003 | 0.89 |
| Functional | ||||||
| Pretreatment UCVA (logMAR) | 0.615 | −0.741-1.972 | 0.37 | −0.0937 | −0.1946-0.0071 | 0.06* |
| Pretreatment BCVA (logMAR) | 3.079 | 0.711-5.448 | 0.01* | −0.4258 | −0.600-−0.251 | <0.001* |
| Anatomical | ||||||
| Pretreatment K-max (D) | −0.041 | −0.112-0.029 | 0.24 | 0.008 | 0.003-0.014 | 0.002* |
| Pretreatment CCT | 0.001 | −0.007-0.011 | 0.72 | −0.0008 | −0.001-0.00002 | 0.057* |
| Pretreatment thinnest point | 0.001 | −0.008-0.011 | 0.71 | −0.0009 | −0.001-−0.0000 | 0.03* |
| Pretreatment deviation index | 0.019 | −0.110-0.150 | 0.76 | 0.009 | −0.001-0.019 | 0.09* |
| Pretreatment corneal asphericity (Q value) | −0.799 | −1.711-0.112 | 0.08* | −0.063 | −0.133-0.006 | 0.07* |
| Pretreatment astigmatism type | ||||||
| ATR | −0.960 | −1.887-−0.033 | 0.10* | 0.032 | −0.043-0.109 | 0.61 |
| Oblique | −0.206 | −1.196-0.782 | 0.032 | −0.046-0.112 | ||
| WTR | Ref | Ref | Ref | Ref | ||
| Pretreatment ARC | 0.595 | −0.168-1.359 | 0.12* | −0.033 | −0.093-0.027 | 0.27 |
| Pretreatment PRC | 0.737 | −0.048-1.523 | 0.06* | −0.036 | −0.1005-0.028 | 0.26 |
| Pretreatment ISV | −0.006 | −0.020-0.007 | 0.38 | 0.0006 | −0.0004-0.0017 | 0.22 |
| Pretreatment IVA | −0.263 | −1.404-0.877 | 0.64 | 0.053 | −0.035-0.142 | 0.23 |
| Pretreatment KI | −1.296 | −5.527-2.934 | 0.54 | 0.227 | −0.106-0.561 | 0.17* |
| Pretreatment CKI | −9.084 | −21.49-3.32 | 0.14* | 0.210 | −0.789-1.209 | 0.67 |
| Pretreatment IHA | −0.011 | −0.031-0.008 | 0.24 | −0.0003 | −0.0018-0.0012 | 0.67 |
| Pretreatment IHD | −2.646 | −10.41-5.11 | 0.50 | 0.324 | −0.289-0.938 | 0.29 |
K-max: Maximum keratometry, BCVA: Best corrected visual acuity, CI: Confidence interval, IL-6: Interleukin-6, TNF-a: Tumor necrosis factor alpha, UCVA: Uncorrected visual acuity, CCT: Central corneal thickness, ATR: Against the rule, WTR: With the rule, ARC: Anterior average radii of curvature, PRC: Posterior average radii of curvature, ISV: Index of surface variance, IVA: Index of vertical asymmetry, KI: Keratoconus index, CKI: Central keratoconus index, IHA: Index of height asymmetry, IHD: Index of height decentration, Ref: Set as reference for analysis, *Those predictors with P < 0.2 in univariate analyses were entered in the multivariable analysis