To investigate if the profiles of GST genotypes were associated with the risk of glaucoma, we first examined the association between combinations of GSTM1 and GSTT1 null genotypes and the risk of glaucoma, in which the reference group consisted of individuals with both putative low-risk genotypes, i.e., the presence of GSTM1 and GSTT1 genotypes [22]. The gene discussed is GSTM1; the disease is glaucoma.