Our results showed that decreased circulating levels of DKK-1 are associated with exudative AMD, but not with atrophic AMD, and the degrees of the DKK-1 decrease are associated with the progression or severity of CNV in exudative AMD; the lower DKK-1 levels in the circulation are associated with the higher likelihood of having exudative AMD. This evidence concerns the gene DKK1 and age-related macular degeneration.