Corneal Safety and Stability in Cases of Small Incision Lenticule Extraction with Collagen Cross-Linking (SMILE Xtra)

Table 1

Preoperative characteristics of the included eyes (60 eyes of 30 patients divided equally into two groups).

	SMILE Xtra () (mean ± SD)	SMILE () (mean ± SD)	value
Male : female	10 : 5	8 : 7	0.456^a
Age (years)	24.3 ± 5.9	25.2 ± 5.1	0.640^b
MRSE (D)	−8.6 ± 1.1	−8.2 ± 1.2	0.411^b
CDVA (logMAR)	0.048 ± 0.06	0.042 ± 0.07	0.341^b
CCT (microns)	495.1 ± 22.6	498.4 ± 21.1	0.245^b
K readings (D)	45.1 ± 1.5	44.6 ± 1.2	0.228^b
ECD (cells/mm^2)	2816 ± 288	2840 ± 278	0.755^b
CRF	10.42 ± 1.68	10.82 ± 1.69	0.287^b
Densitometry	17.31 ± 1.90	16.51 ± 1.71	0.299^b

MRSE: manifest refraction spherical equivalent; K: keratometry; CDVA: corrected distance visual acuity; CCT: central corneal thickness; ECD: endothelial cell density; CRF: corneal resistance factor. ^aChi-squared test; ^bindependent-samples t-test.