Table 4 Keratometry, Q-value and root mean square changes in both treatment groups

K₁ (D)

Preop

43.30 ± 0.24 (42.80, 43.80)

43.30 ± 0.30 (42.80, 43.90)

0.967

Postop

39.00 ± 0.44 (37.80, 39.60)

40.20 ± 0.40 (39.40, 40.90)

0.014

Difference

4.60 ± 0.40 (3.80, 5.40)

3.20 ± 0.40 (2.40, 3.90)

0.007

P value^a

< 0.001

< 0.001

K₂ (D)

Preop

44.80 ± 0.24 (44.30, 45.30)

44.60 ± 0.30 (44.10, 45.20)

0.582

Postop

39.20 ± 0.40 (38.40, 40.10)

40.60 ± 0.40 (39.80, 41.30)

0.026

Difference

5.60 ± 0.40 (4.80, 6.40)

4.10 ± 0.40 (3.30, 4.80)

0.003

P value ^a

< 0.001

< 0.001

K_m (D)

Preop

44.00 ± 0.24 (43.60, 44.50)

44.00 ± 0.30 (43.50, 44.50)

0.852

Postop

39.00 ± 0.44 (38.00, 39.80)

40.40 ± 0.40 (39.60, 41.10)

0.014

Difference

5.10 ± 0.40 (4.40, 5.90)

3.60 ± 0.40 (2.90, 4.40)

0.003

P value^a

< 0.001

< 0.001

Q-value

Preop

− 0.20 ± 0.02 (− 0.25, − 0.17)

− 0.20 ± 0.02 (− 0.25, − 0.16)

0.712

Postop

0.60 ± 0.11 (0.41, 0.84)

0.40 ± 0.08 (0.19, 0.53)

0.089

Difference

0.80 ± 0.10 (0.63, 1.05)

0.60 ± 0.08 (0.40, 0.73)

0.094

P value^a

 < 0.001

 < 0.001

RMSh (μm)

Preop

0.50 ± 0.03 (0.44, 0.55)

0.52 ± 0.04 (0.45, 0.60)

0.658

Postop

1.00 ± 0.07 (0.86, 1.10)

0.83 ± 0.04 (0.74, 0.92)

0.133

Difference

0.50 ± 0.06 (0.38, 0.63)

0.31 ± 0.04 (0.22, 0.40)

0.060

P value^a

< 0.001

< 0.001