HERC2 and Corneal astigmatism: For corneal astigmatism, all four loci identified using the mixed linear model analysis also demonstrated genome-wide significant association using the linear regression model in PLINK, while only two of the three loci originally associated with refractive astigmatism (LINC00340 and HERC2) continued to demonstrate genome-wide significant association (Online Resources 7, 8, 11a, 11c, 12a and 12c).