The demographic information of patients and details of the surgical plan are depicted in
Table 2, and representative images of SMILE-lenticules are shown in
Figures 2A to
2C. The mean power of correction was −2.28 ± 0.21 D for Group 1 (<−3 D), −5.31 ± 1.05 D for Group 2 (−3 to −6 D), and −9.69 ± 0.88 D for Group 3 (>−6 D). There was no significant difference concerning TNL among groups (
P = 0.63, Friedman test,
Fig. 2D). The neurite widths and lengths ranged from 5 to 20 μm and 0.1 to 3.55 mm, respectively (
n = 1360 neurites). Mean lenticule volume was significantly different among groups (
P < 0.05, Friedman test) and mean LND was also significantly higher in Group 1 compared to Groups 2 and 3 (
P < 0.05, Friedman test,
Fig. 2E). Mean LND was 63.41 ± 11.17, 37.45 ± 20.14, and 22.41 ± 4.59 mm/mm
3 for Groups 1 to 3, respectively. The LND showed significant inverse correlation with the power of correction (
r = −0.8925,
P < 0.0001,
Fig. 3A). There was a trend of increasing LND in thinner lenticules (
Fig. 3B). Other parameters, including patient age, preoperative central corneal thickness (CCT), keratometric readings, cap thickness, and lenticule diameters, were not significantly correlated with LND.