Table 7.

Manifest refractive error before and after LASIK

	Refractive Error (D)
	Before	1 year	3 yearsa
Manifest Sphere
Bladeless	−4.02 ± 1.61	−0.31± 0.32	−0.35 ± 0.37
Microkeratome	−4.15 ± 1.62	−0.25 ± 0.33	−0.29 ± 0.35
P	>0.99	>0.99	>0.99
MDD (D)	0.54	0.25	0.24
Manifest Cylinder
Bladeless	0.70 ± 0.82	0.19 ± 0.26	0.10 ± 0.25
Microkeratome	0.77 ± 0.88	0.10 ± 0.20	0.14 ± 0.25
P	>0.99	>0.99b	>0.99
(MDD)	0.41	0.18	0.23

Data are presented as mean ± standard deviation; n=21 unless stated. P-values (paired t-tests unless stated) compare femtosecond laser (bladeless) and microkeratome treatments and were adjusted for 6 comparisons by the Bonferroni technique (comparisons at 1, 3 and 6 months are not shown but were reported previously⁹).

MDD= minimum detectable difference (paired data, α=0.05/6, β=0.20).

^an=20, both eyes of 1 patient excluded because of the presence of cataracts.

^bWilcoxon signed-rank test.