Table 2.
Univariate Analysis and Multivariate Logistic Regression Model for Risk Factors Associated with Keratoconus
| Crude (95% CI) | P-value | Adjust I (95% CI) | P-value | Adjust II (95% CI) | P-value | |
|---|---|---|---|---|---|---|
| Corneal tomographic parameters | ||||||
| Kflat (D) | 0.78 (0.64, 0.94) | 0.009 | 1.00 (0.79, 1.26) | 0.990 | 0.99 (0.73, 1.35) | 0.968 |
| Ksteep (D) | 0.87 (0.74, 1.02) | 0.094 | 1.00 (0.82, 1.22) | 0.979 | 0.89 (0.68, 1.17) | 0.407 |
| Kmax (D) | 0.94 (0.80, 1.10) | 0.413 | 1.07 (0.89, 1.29) | 0.484 | 0.92 (0.71, 1.19) | 0.521 |
| CCT (μm) | 0.99 (0.98, 1.00) | 0.176 | 0.99 (0.98, 1.01) | 0.358 | 0.96 (0.92, 1.00) | 0.043 |
| ACT (μm) | 0.99 (0.98, 1.00) | 0.138 | 0.99 (0.98, 1.00) | 0.267 | 0.95 (0.92, 0.99) | 0.014 |
| TCT (μm) | 0.99 (0.98, 1.00) | 0.045 | 0.99 (0.98, 1.00) | 0.118 | 0.95 (0.91, 0.98) | 0.004 |
| Discrepancy CCT vs TCT (μm) | 1.35 (1.21, 1.51) | <0.001 | 1.38 (1.23, 1.56) | <0.001 | 1.34 (1.15, 1.56) | <0.001 |
| Discrepancy ACT vs TCT (μm) | 1.26 (1.15, 1.40) | <0.001 | 1.25 (1.12, 1.39) | <0.001 | 1.19 (1.02, 1.37) | 0.023 |
| Distance CCT vs TCT# (mm) | 1.14 (1.02, 1.28) | 0.024 | 1.15 (1.01, 1.31) | 0.040 | 1.03 (0.87, 1.23) | 0.719 |
| FE.at.TP (μm) | 1.10 (0.93, 1.31) | 0.261 | 1.20 (0.98, 1.48) | 0.071 | 0.97 (0.74, 1.27) | 0.826 |
| BE.at.TP (μm) | 1.14 (1.05, 1.22) | 0.001 | 1.14 (1.05, 1.24) | 0.003 | 0.99 (0.88, 1.13) | 0.922 |
| ARTmax* | 0.88 (0.84, 0.92) | <0.001 | 0.88 (0.84, 0.93) | <0.001 | 0.83 (0.76, 0.91) | <0.001 |
| ARC (3mm Zone) (mm) | 2.24 (0.83, 6.04) | 0.112 | 0.70 (0.21, 2.40) | 0.575 | 1.17 (0.22, 6.28) | 0.853 |
| PRC (3mm Zone) (mm) | 0.32 (0.11, 0.93) | 0.037 | 0.10 (0.03, 0.37) | 0.001 | 0.09 (0.01, 0.68) | 0.020 |
| Df | 1.00 (0.78, 1.26) | 0.969 | 1.13 (0.86, 1.48) | 0.397 | 0.96 (0.66, 1.39) | 0.823 |
| Db | 0.98 (0.72, 1.32) | 0.892 | 0.96 (0.69, 1.35) | 0.832 | 0.52 (0.30, 0.91) | 0.021 |
| Dp | 2.36 (1.73, 3.22) | <0.001 | 2.35 (1.65, 3.36) | <0.001 | 7.38 (3.28, 16.64) | <0.001 |
| Dt | 1.40 (0.99, 1.98) | 0.054 | 1.36 (0.91, 2.02) | 0.132 | 6.06 (1.63, 22.49) | 0.007 |
| Da | 4.07 (2.52, 6.58) | <0.001 | 3.97 (2.32, 6.78) | <0.001 | 7.23 (2.78, 18.76) | <0.001 |
| BAD D# | 1.11 (1.06, 1.16) | <0.001 | 1.12 (1.06, 1.18) | <0.001 | 1.12 (1.02, 1.23) | 0.024 |
| Corneal biomechanical parameters | ||||||
| IOPnct | 0.65 (0.57, 0.75) | <0.001 | 0.66 (0.57, 0.77) | <0.001 | 0.58 (0.46, 0.73) | <0.001 |
| bIOP | 0.63 (0.54, 0.73) | <0.001 | 0.61 (0.52, 0.73) | <0.001 | 0.53 (0.41, 0.69) | <0.001 |
| SSI# | 0.80 (0.68, 0.95) | 0.010 | 0.85 (0.70, 1.03) | 0.089 | 0.93 (0.70, 1.23) | 0.611 |
| DA.Ratio | 1.95 (1.13, 3.34) | 0.016 | 2.03 (1.05, 3.91) | 0.035 | 1.42 (0.94, 2.16) | 0.099 |
| Integr. Radius | 2.74 (2.02, 3.71) | <0.001 | 2.66 (1.89, 3.76) | <0.001 | 4.64 (2.48, 8.67) | <0.001 |
| ARTh* | 1.03 (1.00, 1.05) | 0.079 | 1.02 (0.99, 1.06) | 0.151 | 1.28 (1.16, 1.41) | <0.001 |
| SP-A1 | 0.99 (0.98, 1.01) | 0.537 | 0.99 (0.97, 1.01) | 0.163 | 0.98 (0.95, 1.02) | 0.384 |
| CBI# | 1.14 (1.03, 1.26) | 0.015 | 1.13 (1.00, 1.27) | 0.053 | 1.12 (0.92, 1.37) | 0.254 |
| TBI# | 1.29 (1.16, 1.43) | <0.001 | 1.28 (1.14, 1.43) | <0.001 | 1.04 (0.84, 1.30) | 0.706 |
Notes: Adjust I model (corneal tomographic parameters): adjusted for sex; age. Adjust II model (corneal tomographic parameters): adjusted for sex; age; IOPnct; bIOP; SSI; DA.Ratio; Interger Radius; ARTh; SP-A1; CBI; TBI. Adjust I model (corneal biomechanical parameters): adjusted for sex; age. Adjust II model (corneal biomechanical parameters): adjusted for sex; age; Kflat; Ksteep; Kmax; CCT; ACT; TCT; Discrepancy CCT vs TCT; Discrepancy ACT vs TCT; Distance CCT vs TCT; FE.at.TP; BE.at.TP; ARTmax; ARC; PRC; Df; Db; Dp; Dt; Da; BAD D. *Every 10 unit increase. #Every 0.1 unit increase.
Abbreviations: K, keratometry; D, diopter; CCT, central corneal thickness; ACT, apex corneal thickness; TCT, thinnest corneal thickness; Discrepancy CCT vs TCT, absolute value of discrepancy between central corneal thickness and thinnest corneal thickness; Discrepancy ACT vs TCT, absolute value of discrepancy between apex corneal thickness and thinnest corneal thickness; Distance CCT vs TCT, absolute value of vector distance between central corneal thickness and thinnest corneal thickness; FE.at.TP, front elevation at thinnest pachymetry; BE.at.TP, back elevation at thinnest pachymetry; ARTmax, maximum Ambrósio relational thickness; ARC, anterior radius of curvature; PRC, posterior radius of curvature; Df, deviation of front elevation difference map; Db, derivation of back elevation difference map; Dp, deviation of average pachymetric progression; Dt, deviation of minimum thickness; Da, deviation of ARTmax; BAD D, Belin/Ambrósio Enhanced Ectasia Deviation; IOPnct, intraocular pressure measured with non-contact tonometer; bIOP, biomechanically-corrected IOP; SSI, stress-strain index; DA, deformation amplitude; Integr. Radius, integrated radius; ARTh, Ambrósio’s relational thickness in the horizontal profile; SP-A1, stiffness parameter at first applanation; CBI, corvis biomechanical index; TBI, Tomography and Biomechanical Index; Crude: no adjustment.