Although TGF-β1 and -β3 were positively correlated to IOP in our study, Pasquale et al.32 reported that in the eye in situ, there was no expression of TGF-β1 and -β3 in the TM of eyes without glaucoma, although TGF-β1 and -β3 may play important roles in the regulation of outflow resistance33,34. This evidence concerns the gene TGFB1 and glaucoma.