Table 3.
Summary of Galilei Keratoconus Parameters in Detecting Pre-Keratoconus
| Study | Cut-off Value | Sensitivity | Specificity | AUC |
|---|---|---|---|---|
| AAI | ||||
| Smadja et al [ 5 ] | 21.5 | 0.936 | 0.972 | - |
| Golan et al [ 7 ] | 13.5 | 0.774 | 0.670 | 0.750 |
| CLMI | ||||
| Shetty et al [ 3 ] | - | - | - | 0.314 |
| CSI | ||||
| Feizi et al [ 4 ] | 0.99 | 0.217 | 1.000 | 0.534 |
| Shetty et al [ 3 ] | 0.90* | 0.973 | 0.047 | 0.556 |
| DSI | ||||
| Feizi et al [ 4 ] | 1.725* | 0.739 | 0.556 | 0.646 |
| Shetty et al [ 3 ] | 1.730 | 0.541 | 0.698 | 0.627 |
| IAI | ||||
| Golan et al [ 7 ] | 0.400 | 0.516 | 0.736 | 0.625 |
| Feizi et al [ 4 ] | 0.445 | 0.739 | 0.541 | 0.664 |
| Shetty et al [ 3 ] | 0.450* | 0.541 | 0.814 | 0.858 |
| I-S | ||||
| Feizi et al [ 4 ] | 1.60* | 0.348 | 0.895 | 0.597 |
| Shetty et al [ 3 ] | 1.60 | 0.108 | 0.907 | 0.595 |
| KPI | ||||
| Feizi et al [ 4 ] | 5.00* | 0.565 | 0.835 | 0.710 |
| Shetty et al [ 3 ] | 5.00 | 0.568 | 0.581 | 0.629 |
| Kprob | ||||
| Feizi et al [ 4 ] | 11.60* | 0.391 | 0.955 | 0.669 |
| Shetty et al [ 3 ] | 11.60 | 0.297 | 0.860 | 0.626 |
| OSI | ||||
| Feizi et al [ 4 ] | 1.850 | 0.304 | 0.985 | 0.637 |
| Shetty et al [ 3 ] | 1.850 | 0.216 | 0.953 | 0.510 |
| Golan et al [ 7 ] | 0.671* | 0.839 | 0.450 | 0.658 |
| PPK | ||||
| Shetty et al [ 3 ] | 25.0 | 0.811 | 0.093 | 0.318 |
| SAI | ||||
| Feizi et al [ 4 ] | 0.895 | 0.435 | 0.917 | 0.644 |
| Shetty et al [ 3 ] | 0.895* | 0.432 | 0.907 | 0.656 |
| SDP | ||||
| Feizi et al [ 4 ] | 1.065 | 0.565 | 0.857 | 0.692 |
| Shetty et al [ 3 ] | 1.065* | 0.892 | 0.814 | 0.916 |
| SRI | ||||
| Feizi et al [ 4 ] | 0.735 | 0.826 | 0.511 | 0.679 |
| Shetty et al [ 3 ] | 0.735* | 0.676 | 0.860 | 0.875 |
| TCP-Central | ||||
| Reddy et al [ 32 ] | 44.12 | 0.170 | 0.670 | 0.510 |
| TCP-Flat | ||||
| Reddy et al [ 32 ] | 43.3 | 0.830 | 0.400 | 0.580 |
| TCP-Steep | ||||
| Reddy et al [ 32 ] | 42.8 | 0.870 | 0.360 | 0.630 |
| Total RMS | ||||
| Reddy et al [ 32 ] | 1.15 | 0.960 | 0.580 | 0.820 |
| Trefoil Z (3,-3) | ||||
| Reddy et al [ 32 ] | -0.08 | 0.610 | 0.580 | 0.540 |
| Vertical Coma | ||||
| Reddy et al [ 32 ] | -0.54 | 0.570 | 0.900 | 0.730 |
| 3rd-order RMS | ||||
| Reddy et al [ 32 ] | 0.78 | 0.710 | 0.900 | 0.830 |
| 4th-order RMS | ||||
| Reddy et al [ 32 ] | 0.37 | 0.710 | 0.830 | 0.790 |
| 5th-order RMS | ||||
| Reddy et al [ 32 ] | 0.09 | 0.670 | 0.820 | 0.800 |
| 6th-order RMS | ||||
| Reddy et al [ 32 ] | 0.05 | 0.620 | 0.780 | 0.740 |
Abbreviations: AAI: Asphericity Asymmetry Index; AUC: Area under the Curve; CLMI: Cone Location and Magnitude Index; CSI: Center/Surround Index; DSI: Differential Sector Index; I-S: Inferior-Superior Index; IAI: Irregular Astigmatism Index; KPI: Keratoconus Probability Index; Kprob: Keratoconus Probability; OSI: Opposite Sector Index; PPK: Percentage Probability of Keratoconus; RMS: Root Mean Square SAI: Surface Asymmetry Index; TCP: Total Corneal Power; SDP: Standard Deviation of Corneal Power; SRI: Surface Regularity Index. *denotes cut-off point with best area under the curve if more than one study evaluated index accuracy. Highlighted indices represent the parameters that had an AUC >0.800, which is the minimum diagnostic accuracy recommended for screening of pre-keratoconus.