Table 1.
Mean pentacam parameters in KCN, fellow eye, and normal groups
| Pentacam parameters | KCN group (n=15), mean (SD) | Fellow eye group (n=15), mean (SD) | Normal group (n=34), mean (SD) |
|---|---|---|---|
| K1 | 45.8 (4.11) | 42.73 (0.99) | 42.95 (1.37) |
| K2 | 49.89 (5.15) | 43.68 (1.11) | 44.03 (1.49) |
| Km | 47.74 (4.52) | 43.21 (1.02) | 43.47 (1.4) |
| Kmax | 57.68 (8.1) | 44.39 (1.15) | 44.57 (1.47) |
| A | 4.09 (2.02) | 0.95 (0.47) | 1.08 (0.64) |
| Q | −0.76 (0.44) | −0.3 (0.14) | −0.29 (0.09) |
| 4 mm I-S | 12.64 (5.91) | 0.27 (0.94) | 0.06 (0.69) |
| 6 mm I-S | 6.45 (4.83) | 0.58 (1.07) | 0.03 (1.09) |
| 4 mm ST-IN | −3.07 (5.92) | −0.04 (0.64) | −0.08 (0.54) |
| 6 mm ST-IN | −2.69 (4.39) | 0.28 (0.59) | 0.1 (0.72) |
| 4 mm SN-IT | −9.12 (6.77) | −0.35 (0.47) | −0.2 (0.59) |
| 6 mm SN-IT | −5.41 (3.1) | −0.21 (2.64) | −0.41 (0.66) |
| CV | 56.99 (2.74) | 58.37 (3.13) | 61.09 (2.62) |
| CTA | 467.8 (28.41) | 515.07 (26.64) | 546.24 (23.99) |
| CTT | 455.13 (29.28) | 512.2 (26.79) | 544.12 (23.46) |
| Y | −0.64 (0.47) | −0.45 (0.18) | −0.3 (0.18) |
| AEmax | 29.67 (16.76) | 3.13 (0.92) | 2.82 (1.03) |
| PEmax | 57.27 (28.14) | 5.27 (2.89) | 4.12 (2.28) |
| AEmin | −10.93 (7.91) | −0.47 (1.64) | −0.26 (0.99) |
| PEmin | −17.87 (14.98) | −1.67 (2.69) | −2.18 (3.5) |
| AEdif | 40.6 (20.24) | 3.6 (1.55) | 3.09 (1.36) |
| PEdif | 75.13 (32.07) | 6.93 (3.28) | 6.29 (3.08) |
| ISV | 102.8 (47.69) | 16.13 (2.47) | 15.62 (4.05) |
| IVA | 1.16 (0.56) | 0.11 (0.04) | 0.11 (0.04) |
| KI | 1.28 (0.18) | 1.02 (0.02) | 1.02 (0.02) |
| CKI | 1.08 (0.07) | 1 (0.01) | 1 (0.01) |
| IHA | 32.13 (34.55) | 5.43 (5.43) | 6.9 (3.23) |
| IHD | 0.15 (0.09) | 0.01 (0.01) | 0.01 (0) |
| Rmin | 5.96 (0.8) | 7.58 (0.18) | 7.58 (0.26) |
| PImax | 3.94 (2.34) | 1.31 (0.16) | 1.17 (0.16) |
| PImin | 1.35 (0.66) | 0.73 (0.11) | 0.65 (0.16) |
| PIavg | 2.3 (1.11) | 1.03 (0.13) | 0.93 (0.12) |
| Df | 10.92 (7.14) | 0.21 (0.93) | −0.08 (1.04) |
| Db | 8.01 (5.78) | −0.04 (0.56) | −0.36 (0.82) |
| Dp | 9.43 (7.5) | 0.83 (0.87) | 0.16 (0.83) |
| Dt | 2.87 (1.19) | 0.81 (0.85) | −0.15 (0.65) |
| Da | 3.1 (0.68) | 0.82 (0.52) | 0.13 (0.64) |
| D | 9.18 (4.06) | 1.18 (0.32) | 0.54 (0.54) |
SD=Standard deviation, n=Number of eyes, KCN=Keratoconus, K1=Flat keratometry, K2=Steep keratometry, Km=Mean keratometry, Kmax=Maximum keratometry, A=Topographic astigmatism, Q=Asphericity for the anterior corneal surface, 4 mm I-S=Keratometry inferior-superior asymmetry at 4 mm, 6 mm I-S=Keratometry inferior-superior asymmetry at 6 mm, 4 mm ST-IN=Superotemporal-inferonasal asymmetry at 4 mm, 6 mm ST-IN=Superotemporal-inferonasal asymmetry at 6 mm, 4 mm SN-IT=Superonasal-inferotemporal asymmetry at 4 mm, 6 mm SN-IT=Superonasal-inferotemporal asymmetry at 6 mm, CV=Corneal volume, CTA=Corneal thickness at the apex, CTT=Corneal thickness at the thinnest point, Y=Y coordinate of the thinnest local, AEmax=Maximum elevation on anterior cornea, PEmax=Maximum elevation on posterior cornea, AEmin=Minimum elevation on anterior cornea, PEmin=Minimum elevation on posterior cornea, AEdif=Elevation differences on anterior cornea, PEdif=Elevation differences on posterior cornea, ISV=Index of surface variance, IVA=Index of vertical asymmetry, KI=Keratoconus-index, CKI=Centre keratoconus-index, IHA=Index of height asymmetry, IHD=Index of height decentration, Rmin=Radii minimum, Df=Belin/Ambrosio enhanced ectasia display value representing the front surface, Db=Back surface, Dp=Pachymetric progression, Dt=Thinnest point, Da=Thinnest point displacement, D=Overall deviation, PImax=Pachymetric progression index maximum, PImin=Pachymetric progression index minimum, PIavg=Pachymetric progression index average.