Table 3 Vector Analysis in all groups using Alpins data analysis

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%)