COL4A3 and keratoconus: One SNP from GWAS was significantly associated with keratoconus, i.e., RXRA-COL5A1 rs1536482 (P = 1.5 × 10−5, I2 = 0), while FOXO1 rs2721051 (P = 9.4 × 10−3, I2 = 0), BANP-ZNF469 rs9938149 (P = 0.017, I2 = 27%), COL4A4 (rs2228557, P = 0.020, I2 = 70%) and COL4A3 (c.2685 A > C, P = 0.032, I2 = 0) were nominally significant (Table 3).