Table 6.

Comparing the studied cases according to I-Trace after 1 year

I-Trace	Pre-operation	Post operation 1 year	p
Defocus (μ)
Positive
Min. – Max.	0.075–6.288	0.023–1.304	Zp=0.109
Mean ± SD.	2.290 ± 1.859	0.266 ± 0.411
Median	2.233	0.069
Negative
Min. – Max.	−1.256 – –0.029	−0.437 – –0.008	–
Mean ± SD.	− 0.319 ± 0.525	−0.112 ± 0.162
Median	−0.101	− 0.046
Astig (μ @)
Min. – Max.	0.014–1.122	0.030–0.619	Zp=0.043*
Mean ± SD.	0.434 ± 0.372	0.237 ± 0.187
Median	0.367	0.170
HO Total (μ)
Min. – Max.	0.066–0.602	0.061–0.500	Zp=0.345
Mean ± SD.	0.271 ± 0.163	0.161 ± 0.115
Median	0.254	0.127
Coma (μ @)
Min. – Max.	0.013–0.298	0.010–0.200	Zp=0.500
Mean ± SD.	0.126 ± 0.087	0.068 ± 0.049
Median	0.114	0.066
Spherical (μ)
Positive
Min. – Max.	0.018–0.135	0.0–0.049	–
Mean ± SD.	0.056 ± 0.038	0.023 ± 0.020
Median	0.047	0.021
Negative
Min. – Max.	−0.472 – –0.003	− 0.169 – –0.001	–
Mean ± SD.	− 0.168 ± 0.206	−0.042 ± 0.046
Median	−0.071	− 0.023
2ry Astig (μ @)
Min. – Max.	0.005–0.331	0.004–0.149	Zp=0.500
Mean ± SD.	0.059 ± 0.081	0.036 ± 0.037
Median	0.033	0.021
Trefoil (μ @)
Min. – Max.	0.026–0.242	0.016–0.340	Zp=0.893
Mean ± SD.	0.117 ± 0.055	0.104 ± 0.088
Median	0.129	0.079
RMS (mm)
Min. – Max.	2.30–5.60	2.0–4.0	tp=0.030*
Mean ± SD.	3.847 ± 1.053	2.767 ± 0.581
Median	3.70	2.60

t: Paired t-test Z: Wilcoxon signed ranks test

p: p value for comparing between pre-operation and final

*: Statistically significant at p ≤ 0.05