The characteristics of the eyes in the NC, CC, and SC groups are shown in the
Table. Among the 121 eyes of myopic subjects (less than –0.5 diopter), there were 66.7% (28/42 eyes) of the individuals in the NC group, 97.3% (36/37 eyes) in the CC group, and 100.0% (42/42 eyes) in the SC group. The age was not significantly different among the three groups (
P = 0.79). The sex distribution was also not significantly different among the three groups (NC vs. CC group;
P = 0.47, CC vs. SC group;
P = 1.00, NC vs. SC group;
P = 0.48). The refractive error of the NC group (–2.35 ± 3.38 D) was significantly greater than that of the CC group (–5.37 ± 3.00 D;
P <0.001) and the SC group (–6.19 ± 2.53 D;
P < 0.001). There was no significant difference in the refractive errors between the CC and SC group (
P = 0.38). The axial length of the NC group (24.60 ± 1.30 mm) was significantly shorter than that of the CC (25.74 ± 1.35 mm;
P < 0.001) and SC groups (25.90 ± 1.38 mm;
P < 0.001). There was no significant difference in the axial length between the CC and SC groups (
P = 0.95). The optic disc tilt in the NC group (24.6 ± 11.2 pixels) was significantly less than that in the CC group (38.6 ± 13.6 pixels;
P < 0.001) and the SC group (48.5 ± 17.3 pixels;
P < 0.001). And the optic disc tilt in the CC group was significantly less than that in the SC group (
P = 0.02). The ovality ratio in the NC group (0.96 ± 0.08) was significantly larger than that in the CC group (0.88 ± 0.09;
P = 0.001) and SC group (0.84 ± 0.13;
P < 0.001), and the ovality ratio in the CC group was significantly larger than that in the SC group (
P = 0.01). The PMP was not significantly different among the three groups (
P = 0.07). The pNFE was more frequently observed in the CC (22/15) and SC groups (31/11) than in the NC group (6/36) but was not significantly different between the CC and SC groups.