Table 2.

Comparison of preoperative and postoperative changes in corneal biometric parameters between the two groups

Parameter	Mean ± Standard Deviation		P-value
	femto-LASIK	flap-off epi-LASIK
K1 (D)
Pre-op	42.65 ± 1.25	42.81 ± 2.09	0.828
Post-op	37.95 ± 2.52	38.04 ± 2.33	0.692
P-value	0.001	< 0.001
K2 (D)
Pre-op	43.79 ± 1.47	43.84 ± 2.11	0.766
Post-op	38.74 ± 2.73	38.61 ± 2.40	0.942
P-value	0.003	< 0.001
CCT (μm)
Pre-op	597.15 ± 27.69	552.15 ± 28.76	0.597
Post-op	475.27 ± 28.89	454.89 ± 43.54	0.086
P-value	< 0.001	< 0.001
ACD (mm)
Pre-op	3.06 ± 0.24	3.28 ± 0.30	0.056
Post-op	2.98 ± 0.22	3.19 ± 0.28	0.066
P-value	0.001	< 0.001
Q-value (Ant.)
Pre-op	−0.41 ± 0.13	−0.39 ± 0.18	0.732
Post-op	0.88 ± 0.65	0.73 ± 0.33	0.732
P-value	0.001	< 0.001
Q-value (Post.)
Pre-op	−0.30 ± 0.11	−0.30 ± 0.08	0.304
Post-op	−0.28 ± 0.10	−0.28 ± 0.09	0.231
P-value	0.068	0.337

femto-LASIK femtosecond laser-assisted in situ keratomileusis; epi-LASIK epipolis laser-assisted in situ keratomileusis; K₁ flattest keratometry reading; D diopters; K₂ steepest keratometry reading; CCT central corneal thickness; Pre-op preoperative; Post-op postoperative; ACD anterior chamber depth (between endothelium to anterior lens surface); Ant. anterior corneal surface; Post. posterior corneal surface; Q-value corneal asphericity