COL4A3 and keratoconus: Genes including VSX1, ZEB1, SOD1, TGFB1, MIR184, COL4A3/COL4A4, RAB3GAP1, LOX, HGF and DOCK9 are reported to be associated with KC [8], and atopy and eye rubbing are considered the two main environmental factors linked to KC [3], [9].