In multivariate analysis, SDD were more likely to be observed with increasing age (OR, 2.4; 95% CI, 1.5–3.9;
P < 0.001 and OR, 4.6; 95% CI, 2.8–7.7;
P < 0.001, respectively, for subjects aged 80–85 years and those aged >85 years), in females (OR, 1.7; 95% CI, 1.2–2.4;
P = 0.005) and in individuals with higher plasma L/Z level (OR, 1.2; 95% CI, 1.0–1.5;
P = 0.039), and less likely in association with lipid-lowering drugs use such as statin and fibrate medications (OR, 0.5; 95% CI, 0.3–0.9;
P = 0.014 and OR, 0.4; 95% CI, 0.2–0.8;
P = 0.012, for statins and fibrates, respectively), and with thicker subfoveal choroidal thickness (OR, 0.8; 95% CI, 0.7–0.9;
P = 0.002) (
Table 5). SDD were positively associated with a history of smoking in the model incorporating clinical, demographic, and axial length characteristics of subjects (OR, 1.6; 95% CI, 1.01–2.37;
P = 0.04), but the association was not significant after adjustment for L/Z supplementation and plasma L/Z levels (OR, 1.3; 95% CI, 0.8–2.00;
P = 0.36;
Table 5). SDD were negatively associated with a lower education level in the model incorporating clinical, demographic, and L/Z supplementation and plasma L/Z levels (OR, 0.4; 95% CI, 0.2–0.93;
P = 0.033, for subjects with shorter secondary school education level;
Table 5).