ROBO1 and age-related macular degeneration: Interaction between ROBO1 SNP rs9309833 and RORA SNP rs8034864 was significant for both wet (Fig. 1C) and early/intermediate dry AMD (Fig. 1D) such that risk of AMD increased according to dose of the rs8034864 G allele among rs9309833 AA homozygotes, whereas AMD risk decreased according to dose of the rs8034864 G allele among rs9309833 GG homozygotes.