Therapeutics Advances
Copyright ©2013 Baishideng Publishing Group Co.
World J Ophthalmol. Aug 12, 2013; 3(3): 20-31
Published online Aug 12, 2013. doi: 10.5318/wjo.v3.i3.20
Table 1 Clinical classification of keratoconus[3]
StageCharacteristics
Stage IEccentric bulging
Induced myopia and/or astigmatism of 5 D
Average central keratometry of 48 D
Stage IIInduced myopia and/or astigmatism of 5 to 8 D
Average central keratometry > 48 D but < 53 D
Absent scarring
Minimum corneal thickness of 400 microns
Stage IIIInduced myopia and/or astigmatism of 8 to 10 D
Average central keratometry > 53 D
Absent scarring
Central corneal thickness of 300 to 400 microns
Stage IVInvaluable refraction
Average central keratometry > 55 D
Central corneal scar
Corneal thickness < 200 microns
Table 2 Paraclinic criteria for diagnosis of keratoconus[4]
CriteriaValues in keratoconus
Curvature> 46 to 47 D
Asymetry I-S> 1.4 D
Irregularity> 20 or 30 degrees with respect to the vertical meridian
Keratometric difference between the 2 eyes> 1 D
Anterior elevation< 15 m in Placido rings images and < 12 m in Scheimpflug images
Posterior elevation< 35 m in Placido rings images and < 18 m in Scheimpflug images
PachymetryThinnest, decentered point, difference of 100 m between center and periphery
Aphericity (Q)Between -0.5 and < -1
EccentricityApproaching 1
Form factorApproaching 0
Corneal irregularity> 1.1-5
Medium toric keratometry47.3-60 D
Surface irregularity index> 1.55
Predicted corneal acuity (Holladay Report)> 0
Keratoconus index (Maeda)> 0
Keratoconus % index> 100
Keratoconus prediction index> 0.38
Surface variation index> 41
Vertical asymmetry index0.32
Keratoconus index> 1.07
Central keratoconus index> 1.03
Smallest curvature radius> 6.71
Largest asymmetry index> 21
Height decentration index> 0.016
Aberration coefficient> 1
AberrationVertical Coma and Coma-like RMS (> 1.5 m)
Corneal volume analysis> 57.98 ± 2.65 mm3
Corneal hysterisis> 9.64 mmHg
Corneal resistance factor> 9.6 mmHg
Table 3 Phakic intraocular lenses for keratoconus studies
Ref.CriteriaLensPreoperativePostoperativeP-value
Leccisotti et al[12]12 eyes. KC I y IIAngular supported, sphericalSphere -10.23 ± 2.85 DSph 0.46 ± 0.45 D0.002
Cyl -2.79 ± 1.11 DCyl -2.35 ± 1 D
CDVA 0.13 ± 0.17UCVA 0.44 ± 0.8
CDVA 0.03 ± 0.05
Alfonso et al[14]25 eyesPosterior chamber, sphericalSph -8.54 ± 4.15 DSph 0.0 ± 0.25 D< 0.05
Cyl -1.24 ± 1.19 DCyl -0.45 ± 0.73 D
CDVA 0.13 ± 0.15SE -0.32 ± 0.55 D
UCVA 0.17 ± 0.19
CDVA 0.12±0.12
Venter et al[15]18 eyesIris supported, toric/sphericalSph -4.64 ± 2.74 DSE -0.46 ± 0.6 D< 0.05
Cyl -3.07 ± 2.04 DUDVA ≥ 0.2 en 94%
CDVA ≥0.5
Alfonso et al[16]30 eyesPosterior chamber, toricSE -5.38 ± 3.26 DSE -0.08 ± 0.37 D
Cyl -3.48 ± 1.24 DCyl 0.41 ± 0.61 D
UDVA 0.8 logMarUDVA 0.10 logMar
CDVA 0.10CDVA 0.10
Kamiya et al[17]27 eyes, mild KCPosterior chamber, toriSE -10.11 ± 2.46 DSE 0.00 ± 0.35 D
Cyl -3.03 ± 1.58 DUCVA -0.09 ± 0.16
UCVA 1.51 ± 0.2CDVA -0.15 ± 0.09
CDVA -0.11 ± 0.08
Sedaghat et al[18]16 eyes,Anterior chamber, iris supportedSph -12.5 ± 4.61 DSph -0.03±1.81 D< 0.0001
Cyl 2.95 ± 4.06 DCyl 2.08 ± 1.04 D
SE -13.9 ± 4.61 DUDVA 0.15 ± 0.13
UDVA CFCDVA 0.11 ± 0.1
CDVA 0.21 ± 0.14
Kato et al[19]36 eyesIris supported, toric, sphericalSE -8.38 ± 3.42 DSE -0.42 ± 0.89 D
Cyl 2.44 ± 2.25 DCyl 0.62 ± 0.69 D
UDVA 1.39 ± 0.42UDVA 0.02 ± 0.21
Hashemian et al[20]22 eyesICL toricSE -4.98 ± 2.63 DSE -0.33 ± 0.51 D
Cyl -2.77 ± 0.99 DCyl -1.23 ± 0.65 D
UDVA 0.63 ± 0.2 dec.UDVA 0. 85 ± 0.21 dec.
Combined procedures
Moshirfar et al[21]19 eyesIntacs/verisyse, sequential vs simultaneousSE -12.38 ± 4.2 DSE -1.2 ± 1.15 DNo difference regarding sequential vs simultaneous
Cyl 3.3 ± 1.8 DCyl 2.06 ± 1.1 D
UCVA 2.025 ± 0.32UCVA 0.465 ± 0.18
CDVA 0.34 ± 0.22CDVA 0.15 ± 0.09
Izquierdo et al[22]11 eyes Progressive KC I and IICrosslinking/verisyseSph -5.7 DSph -0.27 D< 0.05
Cyl -1.45 DCyl -0.9 D
SE -6.42 DSE -0.72 D
UDVA 1.4 ± 0.4UDVA 0.16 ± 0.06
CDVA 0.14 ± 0.06CDVA 0.04 ± 0.05
Alfonso et al[23]40 eyesKeraring/ICLSE -9.65 ± 6.9 DSE -1.2 ± 1.3 D
UDVA 1.0UDVA 0.3
CDVA 0.3CDVA 0.18
Güell et al[24]17 eyes Progressive KC I and IICrosslinking and toric artiflex/artisanSE -6.99 ± 3.2 DSE -0.22 ± 0.33 D
Cyl -3.54 ± 1.38 DCyl -0.62 ± 0.39 D
UDVA < 10.17 ± 013
CDVA 0.1 ± 0.09CDVA 0.10 ± 0.09
Navas et al[25]11 eyes KC I-IVICRS and toric and spherical ICLSph -9.04 ± 6.03 DSph -0.06 ± 0.46 D< 0.01
Cyl -2.95 ± 1.35 DCyl -1.22 ± 0.65 D
SE -10.52 ± 5.88 DSE -0.68 ± 0.45 D
UDVA 1.31 ± 0.37UDVA 0.14 ± 0.04
CDVA 0.289 ± 0.14CDVA 0.16 ± 0.08