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Table 3 Vector Analysis in all groups using Alpins data analysis

From: Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wave front guided surface ablation

Parameter   Group A Group B Group C
Target Induced Astigmatism (TIA)   2.7 ± 0.84 (1.25:4) 3.41 ± 1.13 (1.5:5) 3.03 ± 0.79 (1.75:4.5)
Mean vector 1.45 axis 84 0.94 axis 174 1.21 axis 179
Surgical Induced Astigmatism
(SIA)
  1.66±1.46 (0.3:5.5) 3.47±1.14 (1.5:5.47) 2.9±0.88 (1.5:4.6)
Mean vector 0.88 axis 76 0.93 axis 177 0.84 axis 0
Difference Vector (DV)   2.15±0.62 (1:3.5) 0.53±0.32 (0:1.25) 0.4±0.15 (0.25:0.75)
Mean vector 0.65 axis 95 0.093 axis 133 0.37 axis 177
Magnitude of Error (ME) + =overcorrection
- = undercorrection
-1±1.4 (-2.8:1.79) 0.06±0.35 (-0.74:0.55) -0.13±0.34 (-0.73:0.48)
Correction Index (CI) 1 means ideal 0.47 (0.17:1.6) 1.02 (0.82:1.32) 0.95 (0.67:1.23)
Angle of error (AE) by degrees   -22 ± 49.5 (-156:29.8) 3 ± 3.5 (-3.1:7.22) 0.5 ±2.6 (-2.7:7.20)
Absolute AE by degrees   34 ±42 (2.3:156) 3.14 ± 2.53 (0:7.22) 1.86 ±1.78 (0:7.20)
Torque Effect (TE)   -0.22 ± 1.15 (-2.82:2.25) 0.26 ± 0.45 (-0.43:1.25) 0.02 ± 0.24 (-0.3:0.5)
Flattening Effect (FE)   1.3 ±1.36 (-0.12:4.77) 3.44 ± 1.11 (1.5:5.46) 2.89 ± 0.83 (1.5:4.59)
Index Of Success (IOS)   0.8±0.13 (0.53:1.14) 0.16± 0.1 (0:0.43) 0.13± 0.07 (0.07:0.33)
Percentage of success   19% (14:46.6%) 83.9 % (57:100%) 85.9% (66.7:92.8%)