A method for determining a subject's susceptibility to having or developing age-related macular degeneration, comprising determining in the subject the identity of a chromosome 1 diplotype and a chromosome 10 diplotype, wherein the chromosome 1 diplotype is the diplotype H1_H1, H1_H2, H1_H3, H1_H4, H1_H5, H2_H2, H2_H3, H2_H4, H2_H5, H3_H3, H3_H4, H3_H5, H4_H4, H4_H5, or H5_H5, and the chromosome 10 diplotype is the rsl0490924 SNP in HTRA1 gene, wherein the genotype in the rsl0490924 SNP is GG, GT, or TT, wherein I) the subject is protected against having or developing AMD if the diplotype identified on chromosome 1 includes a risk haplotype and a protective haplotype, as long as the genotype at locus rsl0490924 on chromosome 10 is not the risk genotype TT, wherein the chromosome 1 risk haplotype is H1 or H2 and the chromosome 1 protective haplotype is H3 or H5; or II) the subject has increased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H1_H3 or H1 H5, and the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT; or III) the subject has decreased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H3_H3, H3_H4, or H3_H5, even if the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT. comprising determining in the subject the identity of a chromosome 1 diplotype and a chromosome 10 diplotype, wherein the chromosome 1 diplotype is the diplotype H1_H1, H1_H2, H1_H3, H1_H4, H1_H5, H2_H2, H2_H3, H2_H4, H2_H5, H3_H3, H3_H4, H3_H5, H4_H4, H4_H5, or H5_H5, and the chromosome 10 diplotype is the rsl0490924 SNP in HTRA1 gene, wherein the genotype in the rsl0490924 SNP is GG, GT, or TT, wherein I) the subject is protected against having or developing AMD if the diplotype identified on chromosome 1 includes a risk haplotype and a protective haplotype, as long as the genotype at locus rsl0490924 on chromosome 10 is not the risk genotype TT, wherein the chromosome 1 risk haplotype is H1 or H2 and the chromosome 1 protective haplotype is H3 or H5; or II) the subject has increased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H1_H3 or H1 H5, and the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT; or III) the subject has decreased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H3_H3, H3_H4, or H3_H5, even if the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT. I) the subject is protected against having or developing AMD if the diplotype identified on chromosome 1 includes a risk haplotype and a protective haplotype, as long as the genotype at locus rsl0490924 on chromosome 10 is not the risk genotype TT, wherein the chromosome 1 risk haplotype is H1 or H2 and the chromosome 1 protective haplotype is H3 or H5; or II) the subject has increased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H1_H3 or H1 H5, and the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT; or III) the subject has decreased risk of having or developing AMD if the diplotype identified on chromosome 1 is the protective diplotype H3_H3, H3_H4, or H3_H5, even if the genotype determined at locus rsl0490924 on chromosome 10 is the risk genotype TT.