DKK1 and age-related macular degeneration: Its distribution in exudative AMD was significantly different from that in healthy controls (χ2 = 44.44, P < 0.001) and patients with atrophic AMD (χ2 = 17.78, P < 0.001), with the highest proportion of exudative AMD patients (50/128[39.1%]) in the lowest DKK-1 quartile (Q1, <393.79 pg/mL); while the distribution of DKK-1 quartile having no significant difference between atrophic AMD and healthy controls (χ2 = 2.36, P = 0.50).