Table 2 Clinical characteristics after matching by PSM between the small and large optical zone groups

No. of eyes

78

78

-

Age (y)

23.54 ± 5.63

23.50 ± 5.94

0.927

Gender (M, %)

44%

45%

0.747

Eye (OD, %)

47%

47%

1.000

Preoperative SE (D)

-5.91 ± 0.92

-5.81 ± 0.99

0.484

Mean keratometry (D)

43.17 ± 1.31

43.21 ± 1.27

0.859

Optical Zone (mm)

6.23 ± 0.16

6.53 ± 0.08

< 0.001

Range

6.0 to 6.4

6.5 to 6.8

Postoperative SE (D)

-0.10 ± 0.29

0.02 ± 0.34

0.018